That’s one of the six creative tips offered by Argentine artist Leandro Erlich in a wonderful, small New York Times article. The others are equally good advice, especially for creative professionals.
It’s all about the picture below, provided to The New York Times by Gar Powell-Evans, courtesy of Barbican Art Gallery. Look closely and you’ll understand what it’s all about.
Digital Insider 
Very interesting. Actually, this form of illusion was used by the Allies during WW II to fool Nazis into bombing non-existant targets. Magicians have seemingly made elephants, automobiles and even huge buildings seem to disappear. Regardless, the one you sent is quite an illusion — I love the guy who seems to be hanging by his feet from a window. (copied by HB from an email received from a reader)