3-D Sidewalk Chalk

Last week my niece's and nephew introduced me to 3-D sidewalk chalk while we were in Whistler.

Painting in color, I started to notice their bright shoes (which are always three dimensional). And I began to wonder: Why is 3-D such a big deal, given the fact that we live, move, and breath in 3-D?

(All photos: Whistler, July 2011)