My icons are all floating a tiny bit above my Small upgraded shelf. As you can see, the emblems are firmly on the shelf, but the icons are floating! It looks a bit silly.
http://www.glitch.com/snaps/PHV7J089IN62QQ9/12718-ee014db07e/
You can ignore the floaty fertilidust and cheese on the left, there is a cabinet there I didn't give the time to load before taking the snap, so they are not actually floating.