This is different from the wagon wheel or car wheel in that the wheel's motion is actually smoothly continuous, and other factors chop it up into distinct moments at certain intervals, whereas in the animated image, the actual motion is already inherently chopped up into distinct moments at certain intervals, so no other sources of interferences are necessary to explain why it would look that way.

I did make an animation that proceeds 1° at a time, but that turned out to be the easy part. GIMP is mysteriously insisting on a slow frame rate, so I can't get the rotation speed to be as fast as the rotation speeds of prior examples here. And because so much of the image changes in consecutive frames, the file is over 4 MB anyway, and I don't have a website to host it on. So it won't be posted here unless somebody wants me to email it to him/her and is able to increase the frame rate and host it elsewhere.