Behind the below cut are several pavement drawings done by a UK artist, Julian Beever. His chalk drawings on the pavement differ from those of most people in that they are all done in a distorted fashion so that when they are viewed from a particular angle, they create the impression of depth.
Many pics lurk behind this cut – prepare your browser for bandwidth doom if you are on a modem.
The following picture is an example of a picture taken at the wrong angle, so that you can see the distortion.
This is the same picture from the correct angle