You have to stare at the center of this illusion for at least 30 seconds. In the area of those four small dots. After 20, you might guess what the image is, but continue to stare at it for the full 30 seconds. Then quickly look at a white wall or a white piece of paper and begin to blink quickly.
Awesome isn't it?! I thought it was just awesome. No other word for it. God bless!