There's currently a glaring oversight with product variant photos and the 'default' photo hindering them being displayed in search results. Please see below. If you agree, and suffer from the same issue, please raise it with eBay as they will only change with enough noise. Clearly an oversight with a simple fix.

Case 1: With a ‘Default’ photo set, although it looks correct when searching for “Fresh Fruit”, when searching for the specific variant “Apple” the default photo is still being used. Users quickly glancing at search results might just buy from the competitor selling a rival individual apple. Surely the ‘Default’ photo should only be used for general search terms or general listings, but the variant photo should be used for the specific variant search?
Case 2: In order to compete and stay relevant for individual variants in searches we are having to set ‘No’ default photo, which then randomises product photos in general search results but then selects relevant product variants for specific terms. Additionaly, our listing thumbnail now appears broken if showcases in the store page or marketing/newsletter channels. Sadly this is neccessary currently to compete on “Apple” search terms
The Fix? Allow us to correctly set a default photo without it hindering invidivudal variant photos. Correctly serve the individual product variants images to relevant search terms, and for broader terms or store/shop/marketing/channel views serve the generic default image. Allow us to compete on “Apple” and still have a nice “Default” photo.