There's some posts about this in the iOS 7 Music App thread.
I think it's silly because it takes up so much visual space (can only see 3.5 artists at once on my 4S), and I can't recognize anyone anyways... all the photos are tiny, artistic (black and white, high contrast) of a person or small group of people. You likely have never seen the photo before, so it's of no use when browsing.
/rant. Sorry!