You can choose images you want to appear for each of the languages, you'll need to edit the HTML of the theme for that. There is quite a helpful article on that available on Shopify Help section, https://help.shopify.com/en/manual/using-themes/translate-theme#using-the-language-editor-to-add-tra...
You can also consider using third-party apps while you have only one language, because it gets harder to switch if you already have multiple languages created manually through Shopify.
One of the apps that can help you is GTranslate, it translates the content of your website automatically to 100+ languages, and the paid plans also allow you to edit these translations if you don't like any of those.
It also provides you the possibility to edit the HTML content of the page for each of the translated languages, as well as a more intuitive way for changing images depending on the language. It provides an intuitive In-Context editor, which overlays your website, so you can see the content you're editing.
Other benefits include but are not limited to
You can give it a try at https://apps.shopify.com/multilingual-shop-by-gtranslate, or contact livechat at https://gtranslate.io to get more details.