Hi,
ich weiss nicht, wie firm Du in Sachen Programmierung bist, aber ich geb Dir mal den ersten Anstoß:
Du solltest dazu in der Datei sections/hero.liquid arbeiten. Am Ende dieser Datei ist das Schema definiert, das die Datenstruktur beschreibt. Hier kannst Du den entsprechenden Inhaltsblock der Bildauswahl (sollte Zeile 122-137 sein) duplizieren – das gibt Dir ein zweites Bildelement und das kannst Du als “Foto mobil” bezeichnen, oder wie auch immer du willst – und musst dem eine eindeutige ID geben (in meinem Beispiel image-mobile). Der markierte Teil ist der eingefügte Block.
Jetzt hast Du im Customizer ein zweites Bildauswahlelement:
Das mobile Bild kannst Du jetzt hier ablegen.
Der zweite Teil ist, dass Du in der Darstellungslogik die Bilder je nach Kontext (mobile/desktop) anzeigen lässt. Dazu musst Du den Template Code von hero.liquid (der Code am Dateianfang) erweitern.
Ich hab hier ein (ungetestetes) Beispiel implementiert, das so schon funktionieren könnte 
{%- if section.settings.hero_layout == 'full_width' and section.settings.hero_size == 'adapt' -%}
{%- if section.settings.image.aspect_ratio == blank -%}
{%- assign min_aspect_ratio = 2.0 -%}
{%- else -%}
{%- assign min_aspect_ratio = section.settings.image.aspect_ratio -%}
{%- endif -%}
{%- if section.settings.image.aspect_ratio_mobile == blank -%}
{%- assign min_aspect_ratio_mobile = 1.0 -%}
{%- else -%}
{%- assign min_aspect_ratio_mobile = section.settings.image.aspect_ratio_mobile -%}
{%- endif -%}
{%- assign wrapper_height = 100 | divided_by: min_aspect_ratio -%}
{%- assign wrapper_height_mobile = 100 | divided_by: min_aspect_ratio_mobile -%}
{%- style -%}
@media screen and (min-width: 67.5em) {
.hero-{{ section.id }}.hero-{{ section.id }} {
height: {{- wrapper_height -}}vw !important;
}
}
.hero-{{ section.id }} {
height: {{- wrapper_height_mobile -}}vw !important;
}
{%- endstyle -%}
{%- endif -%}
{%- if section.settings.hero_layout == 'fixed_width' -%}
{%- endif -%}
{%- if section.settings.hero_layout == 'fixed_width' and section.settings.hero_size == 'adapt' -%}
{%- assign slide_width = 1090 -%}
{%- assign slide_mobile_width = 480 -%}
{%- assign min_aspect_ratio = section.settings.image.aspect_ratio | default: 2.0 -%}
{%- assign min_aspect_ratio_mobile = section.settings.image_mobile.aspect_ratio | default: 1.0 -%}
{%- assign img_url = section.settings.image | img_url: '1x1' | replace: '_1x1.', '_{width}x.' -%}
{%- assign img_url_mobile = section.settings.image_mobile | img_url: '1x1' | replace: '_1x1.', '_{width}x.' -%}
{%- if section.settings.image.width < max_width -%}
{%- assign slide_width = section.settings.image.width -%}
{%- endif -%}
{%- if section.settings.image_mobile.width < max_width -%}
{%- assign slide_mobile_width = section.settings.image_mobile.width -%}
{%- endif -%}
{%- if section.settings.title != blank -%}
## {{ section.settings.title | escape }}
{%- endif -%}
{%- if section.settings.text != blank -%}
{{ section.settings.text }}
{%- endif -%}
{%- if section.settings.button_label != blank and section.settings.button_link != blank -%}
{{ section.settings.button_label | escape }}
{%- endif -%}
{%- if section.settings.image != blank -%}
{%- else -%}
{% capture current %}{% cycle 1, 2 %}{% endcapture %}
{{ 'lifestyle-' | append: current | placeholder_svg_tag: 'placeholder-svg' }}
{%- endif -%}
{%- if section.settings.image_mobile != blank -%}
{%- else -%}
{% capture current %}{% cycle 1, 2 %}{% endcapture %}
{{ 'lifestyle-' | append: current | placeholder_svg_tag: 'placeholder-svg' }}
{%- endif -%}
{%- else -%}
{%- if section.settings.image == blank -%}
{{ 'lifestyle-1' | placeholder_svg_tag: 'placeholder-svg' }}
{%- endif -%}
{%- if section.settings.image_mobile == blank -%}
{{ 'lifestyle-1' | placeholder_svg_tag: 'placeholder-svg' }}
{%- endif -%}
{%- if section.settings.title != blank -%}
## {{ section.settings.title | escape }}
{%- endif -%}
{%- if section.settings.text != blank -%}
{{ section.settings.text }}
{%- endif -%}
{%- if section.settings.button_label != blank and section.settings.button_link != blank -%}
{{ section.settings.button_label | escape }}
{%- endif -%}
{%- endif -%}
{%- if section.settings.hero_layout == 'fixed_width' -%}
{%- endif -%}
{% schema %}
{
"name": {
"de": "Foto mit überlegtem Text",
"en": "Image with text overlay",
"es": "Imagen con texto",
"fr": "Image avec texte",
"it": "Immagine con testo",
"ja": "テキストオーバーレイ付き画像",
"nl": "Foto met tekstoverlay",
"pt-BR": "Imagem com texto",
"zh-CN": "带文本叠加的图片",
"zh-TW": "附文字疊加的圖片"
},
"class": "index-section index-section--flush",
"settings": [
{
"type": "image_picker",
"id": "image",
"label": {
"de": "Foto",
"en": "Image",
"es": "Imagen",
"fr": "Image",
"it": "Immagine",
"ja": "画像",
"nl": "Afbeelding",
"pt-BR": "Imagem",
"zh-CN": "图片",
"zh-TW": "圖片"
}
},
{
"type": "image_picker",
"id": "image-mobile",
"label": {
"de": "Foto mobil",
"en": "Image mobile",
"es": "Imagen [m]",
"fr": "Image [m]",
"it": "Immagine [m]",
"ja": "画像 [m]",
"nl": "Afbeelding [m]",
"pt-BR": "Imagem [m]",
"zh-CN": "图片 [m]",
"zh-TW": "圖片 [m]"
}
},
{
"type": "select",
"id": "alignment",
"label": {
"de": "Fotoausrichtung",
"en": "Image alignment",
"es": "Alineación de imagen",
"fr": "Alignement de l'image",
"it": "Allineamento immagine",
"ja": "画像アラインメント",
"nl": "Afbeelding uitlijnen",
"pt-BR": "Alinhamento da imagem",
"zh-CN": "图片对齐方式",
"zh-TW": "圖片對齊"
},
"default": "center",
"options": [
{
"value": "top",
"label": {
"de": "Oben",
"en": "Top",
"es": "Superior",
"fr": "Haut",
"it": "In alto",
"ja": "上",
"nl": "Boven",
"pt-BR": "Acima",
"zh-CN": "顶部",
"zh-TW": "頂部"
}
},
{
"value": "center",
"label": {
"de": "Mitte",
"en": "Middle",
"es": "Al medio",
"fr": "Milieu",
"it": "Al centro",
"ja": "中央",
"nl": "Midden",
"pt-BR": "Meio",
"zh-CN": "中间",
"zh-TW": "中央"
}
},
{
"value": "bottom",
"label": {
"de": "Unten",
"en": "Bottom",
"es": "Inferior",
"fr": "Bas",
"it": "In basso",
"ja": "下",
"nl": "Onder",
"pt-BR": "Abaixo",
"zh-CN": "底部",
"zh-TW": "底部"
}
}
]
},
{
"type": "select",
"id": "hero_layout",
"label": {
"de": "Layout",
"en": "Layout",
"es": "Diseño",
"fr": "Mise en page",
"it": "Layout",
"ja": "レイアウト",
"nl": "Indeling",
"pt-BR": "Layout",
"zh-CN": "布局",
"zh-TW": "版面配置"
},
"default": "full_width",
"options": [
{
"label": {
"de": "Volle Breite",
"en": "Full width",
"es": "Ancho completo",
"fr": "Pleine largeur",
"it": "Intera larghezza",
"ja": "全幅",
"nl": "Volledige breedte",
"pt-BR": "Largura completa",
"zh-CN": "全宽",
"zh-TW": "全寬度"
},
"value": "full_width"
},
{
"label": {
"de": "Feste Breite",
"en": "Fixed width",
"es": "Ancho fijo",
"fr": "Largeur fixe",
"it": "Larghezza fissa",
"ja": "固定幅",
"nl": "Vaste breedte",
"pt-BR": "Largura fixa",
"zh-CN": "固定宽度",
"zh-TW": "固定寬度"
},
"value": "fixed_width"
}
]
},
{
"type": "select",
"id": "hero_size",
"label": {
"de": "Bereichs-Höhe",
"en": "Section height",
"es": "Altura de la sección",
"fr": "Hauteur de la section",
"it": "Altezza sezione",
"ja": "セクションの高さ",
"nl": "Sectiehoogte",
"pt-BR": "Altura da seção",
"zh-CN": "分区高度",
"zh-TW": "區塊高度"
},
"default": "medium",
"options": [
{
"label": {
"de": "An Bild anpassen",
"en": "Adapt to image",
"es": "Adaptar a la imagen",
"fr": "S'adapter à l'image",
"it": "Adatta all'immagine",
"ja": "画像に適応する",
"nl": "Aanpassen aan afbeelding",
"pt-BR": "Adaptar à imagem",
"zh-CN": "适应图片",
"zh-TW": "配合圖片"
},
"value": "adapt"
},
{
"label": {
"de": "Extra klein",
"en": "Extra Small",
"es": "Extra pequeña",
"fr": "Très petite",
"it": "Molto piccola",
"ja": "極小",
"nl": "Extra klein",
"pt-BR": "Extra pequeno",
"zh-CN": "特小",
"zh-TW": "超小型"
},
"value": "x-small"
},
{
"label": {
"de": "Klein",
"en": "Small",
"es": "Pequeña",
"fr": "Petite",
"it": "Small",
"ja": "小",
"nl": "Klein",
"pt-BR": "Pequeno",
"zh-CN": "小",
"zh-TW": "小型"
},
"value": "small"
},
{
"label": {
"de": "Mitte",
"en": "Medium",
"es": "Mediana",
"fr": "Moyenne",
"it": "Medium",
"ja": "中",
"nl": "Gemiddeld",
"pt-BR": "Médio",
"zh-CN": "中等",
"zh-TW": "中等"
},
"value": "medium"
},
{
"label": {
"de": "Groß",
"en": "Large",
"es": "Grande",
"fr": "Grande",
"it": "Large",
"ja": "大",
"nl": "Groot",
"pt-BR": "Grande",
"zh-CN": "大",
"zh-TW": "大型"
},
"value": "large"
},
{
"label": {
"de": "Extra groß",
"en": "Extra Large",
"es": "Extra grande",
"fr": "Très grande",
"it": "Molto grande",
"ja": "特大",
"nl": "Extra groot",
"pt-BR": "Extra grande",
"zh-CN": "特大",
"zh-TW": "超大型"
},
"value": "x-large"
}
]
},
{
"type": "select",
"id": "text_size",
"label": {
"de": "Textgröße",
"en": "Text size",
"es": "Tamaño del texto",
"fr": "Taille du texte",
"it": "Dimensione testo",
"ja": "文字サイズ",
"nl": "Tekengrootte",
"pt-BR": "Tamanho do texto",
"zh-CN": "文本大小",
"zh-TW": "文字尺寸"
},
"default": "medium",
"options": [
{
"label": {
"de": "Mitte",
"en": "Medium",
"es": "Mediano",
"fr": "Moyenne",
"it": "Medium",
"ja": "中",
"nl": "Gemiddeld",
"pt-BR": "Médio",
"zh-CN": "中等",
"zh-TW": "中等"
},
"value": "medium"
},
{
"label": {
"de": "Groß",
"en": "Large",
"es": "Grande",
"fr": "Grande",
"it": "Large",
"ja": "大",
"nl": "Groot",
"pt-BR": "Grande",
"zh-CN": "大",
"zh-TW": "大型"
},
"value": "large"
}
]
},
{
"type": "text",
"id": "title",
"label": {
"de": "Titel",
"en": "Heading",
"es": "Título",
"fr": "En-tête",
"it": "Heading",
"ja": "見出し",
"nl": "Kop",
"pt-BR": "Título",
"zh-CN": "标题",
"zh-TW": "標題"
},
"default": {
"de": "Foto mit überlegtem Text",
"en": "Image with text overlay",
"es": "Imagen con texto",
"fr": "Image avec superposition de texte",
"it": "Immagine con testo",
"ja": "テキストオーバーレイ付き画像",
"nl": "Foto met tekstoverlay",
"pt-BR": "Imagem com sobreposição de texto",
"zh-CN": "带文本叠加的图片",
"zh-TW": "附文字疊加的圖片"
}
},
{
"type": "richtext",
"id": "text",
"label": {
"de": "Text",
"en": "Text",
"es": "Texto",
"fr": "Texte",
"it": "Testo",
"ja": "テキスト",
"nl": "Tekst",
"pt-BR": "Texto",
"zh-CN": "文本",
"zh-TW": "文字"
},
"default": {
"de": "
Nutzen Sie überlegten Text, um Kunden über Ihre Marke zu informieren. Wählen Sie Fotos und Text aus, die zu Ihrer Marke passen.
",
"en": "
Use overlay text to give your customers insight into your brand. Select imagery and text that relates to your style and story.
",
"es": "
Usa el texto superpuesto para darles información a tus clientes sobre tu marca. Selecciona imágenes y textos que se relacionen con tu estilo e historia.
",
"fr": "
Utilisez la superposition de texte pour donner un aperçu de votre marque à vos clients. Utilisez une image et du texte qui se rapportent au style et à l'histoire de votre marque.
",
"it": "
Utilizza il testo in sovrapposizione per dare ai clienti informazioni sul tuo brand. Seleziona immagini e testo legati al tuo stile e alla tua storia.
",
"ja": "
オーバーレイテキストを使用して、お客様があなたのブランドについてよく理解できるようにします。あなたのスタイルやストーリーに関連する画像やテキストを選択してください。
",
"nl": "
Gebruik overlay-tekst om uw klanten inzicht te geven in uw merk. Selecteer afbeeldingen en tekst die betrekking hebben op uw stijl en verhaal.
",
"pt-BR": "
Use o texto de sobreposição para apresentar informações sobre sua marca aos clientes. Selecione imagens e textos que reflitam seu estilo e sua história.
",
"zh-CN": "
使用叠加文本让客户深入了解您的品牌。选择与您的风格和故事相关的图片和文本。
",
"zh-TW": "
運用文字疊加讓客戶更加瞭解您的品牌。選擇與您風格和品牌故事相關的圖像和文字。
"
}
},
{
"type": "text",
"id": "button_label",
"label": {
"de": "Button-Etikett",
"en": "Button label",
"es": "Etiqueta de botón",
"fr": "Texte du bouton",
"it": "Etichetta pulsante",
"ja": "ボタンラベル",
"nl": "Knoplabel",
"pt-BR": "Etiqueta do botão",
"zh-CN": "按钮标签",
"zh-TW": "按鈕標籤"
}
},
{
"type": "url",
"id": "button_link",
"label": {
"de": "Button-Etikett",
"en": "Button link",
"es": "Enlace de botón",
"fr": "Lien du bouton",
"it": "Link pulsante",
"ja": "ボタンリンク",
"nl": "Knoplink",
"pt-BR": "Link do botão",
"zh-CN": "按钮链接",
"zh-TW": "按鈕連結"
}
}
],
"presets": [
{
"name": {
"de": "Foto mit überlegtem Text",
"en": "Image with text overlay",
"es": "Imagen con texto",
"fr": "Image avec superposition de texte",
"it": "Immagine con testo",
"ja": "テキストオーバーレイ付き画像",
"nl": "Foto met tekstoverlay",
"pt-BR": "Imagem com sobreposição de texto",
"zh-CN": "带文本叠加的图片",
"zh-TW": "附文字疊加的圖片"
},
"category": {
"de": "Foto",
"en": "Image",
"es": "Imagen",
"fr": "Image",
"it": "Immagine",
"ja": "画像",
"nl": "Afbeelding",
"pt-BR": "Imagem",
"zh-CN": "图片",
"zh-TW": "圖片"
}
}
]
}
{% endschema %}