Not exactly. The main gallery image (indeed, all images) needs to match the item the listing is for, and the one policy that addresses this problem is rarely, if ever, enforced (that one being a seller is not allowed to include completely different items in a single variation listing, making it so that a listing for high-end watches including a $1 screwdriver or what have you, are technically against policy)
Fun fact - when eBay first introduced variation listings, the gallery image in search results correlated to the variation the buyer searched for, if the seller had uploaded images for individual variations. It was in very limited categories at first, clothing being one of the few that had it, so as an example, if a listing had a dress in 3 different colours (say red, black and blue), and one searched for "red dress", the gallery image and display price was for the "red dress" variation. I know this because I sold clothing when they introduced the feature, and tested it every which way I could think of.
When the feature expanded to other categories, eBay limited its function, and the gallery image plus price changing according to what brought it up in search results stopped all together.
TL;DR - eBay deliberately removed the ability to see what item and price matched in search results.
