From the outside, I'd just like to point out that the image has been doctored slightly. That doesn't make it any less impressive, in my mind. After all, magicians employ tricks all the time, which don't make the feats any less impressive or entertaining.
So what is "Waterfall"? And who is Escher?
To start in reverse order, Escher was a graphic artist who created many interesting pieces of art, all with a geeky, technical, bent. He drew and sculpted complex tessellations, impossible objects, and other mathematically curious objects. The Waterall was a piece from 1961 that shows an (apparent) paradox where water from the base appears to run uphill, before reaching the top of the waterfall.
Escher was/is the geek's artist. ANd LEGO is the geek's toy. So what else do you want?