The primary product photograph or 3D render displayed in Amazon search results and the first slot of the detail page gallery. Amazon Seller Central strictly mandates a pure white background (RGB 255, 255, 255), at least 85% frame fill, and prohibits added text, badges, borders, or non-included accessories.
A kitchen brand optimizing their MAIN image from 85% basic fill to 92% mobile framing with ray-traced contact shadows increased mobile click share by 24% without changing PPC bids.