Mark Wyner Won’t Comply 
These cubes aren’t moving or changing (as implied by the arrows). At all. Not even a little. Other than the color toggle, they remain constant.
(Credit: Ja Gari Kin)
EDIT: added content warning because of the flashing.
Stevens R MillerThey don't move, but the black/white isn't just toggling. Capture two frames of motion about three or four frames apart and compare them. Here, I've done that when they are appearing to rotate, and put one frame in the upper half, the other frame in the lower half. You can see the gradient.
Inc Hulk 🧪@stevensrmiller @markwyner The actual shapes do not move, the colours within the vertical/horizontal bars of the boxes do move (thick white + thin black to thin black + thick gray for example).
Yes. It wouldn't work if the lines were too thin to show multiple bands. Still quite fascinating, even when you know how it works.