Optical Illusion?

I saw a series of display regarding this at the MIT Museum last weekend, I was so impressed by this optical illusion, which the scientists explained as people's perception regarding if they take in more detailed information at a closer distance vs. a more general impression at a further distance... A related article was found on the web with the images, reposted here below for your enjoyment:

Mr Angry is on the left of the screen and Mr Calm is on the right of the screen. Move back about 8 feet and they have switched places. Source:Matthewroddy

Similar to the Angry Illusion, Marilyn Monroe

and Albert

embed themselves together in this illusion. You will see Einstein

at this reading distance but move back a few feet away and you will see Marilyn Monroe.