That was freakin sick.
someone explain why!!
Technically it's not an illusion. It is a "stabilized image". In order to keep seeing our eyes continuously "scan" the image we are looking at. They are doing so by involuntary eye movements. (Even when we think we are fixating at one single point, our "gaze" is wandering around this point). If these small eye movements are stopped or the image is stabilized on the retina by other means the image starts to fade probably due to some adaptational mechanism. (Search for "stabilized images")This image is not "stabilized" but it is blurry. In particular, each part of the image is very similar to its surroundings (even the edges are blurred to white) within a range equal to the range randomly "scanned" by involuntary eye movements. This means that if you fixate at any point on the image then each part of your retina is receiving pretty much the constant luminance and color information over time. In this manner this image behaves like a stabilized image. I am predicting that If you look at this image from a distance (or zoom out to make it small) the "illusion" will not work anymore. (Study in Greece: Nice weather, great food, kind people, no money, no stress, professors read blameitonthevoices)
A better example:http://artoftrolling.memebase.com/2011/10/10/illusion-troll-wait-for-it/