I created the pinwheel GIF animation below in Adobe Photoshop.
Technical details: I scanned the image and cropped it to be square and centered. I duplicated the first layer and rotated it one degree, duplicated the new layer, rotated, and repeated until I had 72 layers. There are 360 degrees in a circle, and since there are 5 vanes in the pinwheel, and 360 ÷ 5 = 72, I needed 72 layers to make it turn 1/5th of the way around.
In the Animation window, I made each layer start one frame later than the previous one. It looked like a staircase when I was done.
The animation goes 1/5 of the way around, then repeats infinitely, so it only appears to spin all the way around. Each layer is a frame and it runs at a standard 30 frames per second, which looks smooth to the eye.
Because it’s hand-drawn and not totally perfect, there’s a bit of a jump at the juncture, which seems to have a lot to do with how Photoshop rendered the rotated layers, as well as the fact that the image is hand-drawn and not perfect.
Staring at the pinwheel then looking away at the text makes the text seem to spin – for me, anyway.