That's wild. Originally I saw her as definitely spinning clockwise (was seen from above). Then I looked at the shadow and saw her as spinning counterclockwise. Now I can't switch back to the former view, even if I cover up the shadow part of the image. It's "locked" in my brain now. I'm trying to figure out what cues indicate clockwise or counterclockwise, but can't really tell. Seems like it's intuitive, but the original intuition was incorrect.
If you look at the shadow of her right foot and picture it moving either in front of or behind the shadow of her left foot, you can switch the direction in which she's spinning (or your perception of the direction).