What Watch icon...? I've never seen one when I'm searching - I've always had to click on a listing before being able to add it to Watch.
I'm not seeing heart icons on listings either. Perhaps it's something Ebay are testing (which they would do with randomly-selected accounts) as lots of other platforms and retailers already use them (so that shoppers can easily add items to their favourites lists). Where exactly are you seeing this...? Can you provide a screen shot...?
