Looking at a moving illusion is always a little freaky. On one hand, your brain knows that the image is a still image and can’t be moving, but on the other hand, your eyes comprehend movement.
But, what makes a moving illusion appear to move? Moving illusions are still a bit of a mystery. but one theory involved how our brains perceive different colors. We perceive some colors faster or slower than other colors, giving the illusion of movement even in some still images.
This illusion, for instance, is made from diagonal stripes of different colors and white and black squares.
Does this look like it’s moving to you? Try running your eyes slowly over the image, then staring at the center. Does it move differently depending on how you look at it?