Hey, this is a really common gotcha with store duplication and it’s almost never actually a “bug” — it’s usually one of these three things, in order of likelihood:
1. The image file itself is slightly different between stores
When a store gets duplicated, images sometimes get re-uploaded/re-processed through Shopify’s CDN rather than copied byte-for-byte, and if the duplication tool re-compresses or re-exports the image, its native pixel dimensions (and therefore aspect ratio) can shift by a tiny amount. If your section is using object-fit: cover or contain with a fixed-height container, even a 1-2% aspect ratio difference will change how much empty space shows up on the sides. Worth checking: right-click the image on both stores and compare the actual file dimensions (or check Settings > Files in admin) — if they’re not pixel-identical, that’s your answer.
2. A section setting didn’t carry over exactly
A lot of “duplicate store” methods (whether it’s Shopify’s own duplicate feature, a duplication app, or a manual theme export/import) copy theme code faithfully but don’t always copy section settings with 100% fidelity — especially anything stored as a slider value (like “image width” or “column ratio”) rather than a fixed preset. If your section has a setting like “Desktop image width %” or similar, check that value on both stores side by side in the theme editor. It’s an easy thing to miss because visually the section looks “close enough” until you check pixel-for-pixel.
3. Responsive image srcset serving a different breakpoint
Shopify auto-generates multiple image sizes via image_url/srcset, and the browser picks whichever fits the container best. If the container width calculation differs even slightly between the two stores (because of #1 or #2 above), the browser may pull a different srcset breakpoint, which can also shift the rendered box size — this compounds the visual difference rather than causing it on its own.
How I’d debug it
Open both stores side by side in browser DevTools, inspect the image element on each, and compare the actual computed width/margin/padding values (not just what the theme editor shows). That’ll tell you immediately whether it’s a CSS/layout issue or an image-file issue. If the computed CSS values are identical but it still looks different, it’s the image file. If the CSS values differ, it’s the section setting.
Since you mentioned Claude wasn’t able to fix it either — that tracks, because without being able to actually inspect the live DOM/computed styles side-by-side (or compare the two image files’ raw dimensions), it’s guessing at a layout fix for something that’s likely a data difference, not a code difference. Pulling the computed styles from both sites and comparing them directly is what’ll actually surface the cause here.
