Ilusão de ótica no jogo de tênis pra ajudar a exercitar o cérebro

http://www.neatorama.com/2014/01/29/Optical-Illusion-Tennis-Match/

via Byline

I think this is how M.C. Escher played tennis! Imgur user cynicalnihilisticromantist submitted this photo of an optical illusion tennis match - or is it just a regular tennis match being played down under in Australia?