In the *Now Playing* panel, hovering over the artwork gives a tooltip giving info like image res, artist, album name, etc.
My default browsing view is *Track details* but I like using *Artwork* so I can right click and 'search artwork'.
So, if a tooltip pops up when pointing at the album art directly from the main view then it would be great. I like making sure all my artwork are exactly square and high resolution when possible.