Mighty Optical Illusion

One the right you see the silhouette of a spinning figurine. Does she spin clockwise or opposite?

If you look at the spinning girl's silhouette below, you will think it is spinning clockwise, probably. When you check her shadow below, momentarily the spinning direction changes in your mind, and now the girl is spinning counter-clockwise. It can be quite hard at the beginning to notice switch of the spinning direction, but eventually you'll manage.
I've found that if you cover image apart from the shadow of the feet and concentrate on seeing them rotate in the opposite direction, when you uncover the image, it too will seem to be in a reverse spin.
If you got friends in the same room with you ask them what they see, and you'll be surprised !