From Michael’s “Optical Illusions & Visual Phenomena“
What to observe. Above, the tiles are moving left and right in alternating rows. In the ‘half-shifted condition’, the ‘mortar lines’ (the horizontal lines between the tiles) appear to slope alternately upward and downward. This gives the impression that the tiles are wedge-shaped. As seen when the tiles align or make up a chequerboard, the lines are actually parallel, and all tiles are perfectly square and of the same size. So during the movement, the illusion “comes and goes”.
Hey this is just fantastic, im never seen so many illusions like that before. Its actually quite freaky lol, and the one that I found amazing was the motion induced blindness