Don't know if this has been posted before.
The Right Brain vs Left Brain | Frostfirezoo.com
Is the dancer going left to right, right to left, or both?
I usually see it going clockwise, but sometimes I see it going counter-clockwise.
I do not think that it has anything to do with right or left brain usage, but it's interesting since the image is just repeating itself over and over the same way.