Drawing Hands: This is one of M.C. Escher's marvelous impossible instances (drawn in 1948) and one of the rare moments to be part of a visual game in which a flat pattern is transformed into a three-dimensional object.
In this image there is a piece of paper pinned down and on this drawing paper a right hand and a left hand are apparently in the act of drawing one another into existence.
It is a strange loop, a case of self-reference, a trick to turn a flat surface into a spacial perplexity!!!