Floating vase------unknown artist (trikly)

Shadow is the key to scale the object's height and depth.

Normaly, the shadow projected with the vase by light on the surface. In this image, the light has been arranged which projected a circle shadow is not follow the vase, so the vase looks like floating.
This is the way to show the version illusion.
http://www.163vc.com/imgpop/48354.html