Originally Posted by MonsterD
Took me a little but but yeah she is changing her rotating direction every half rotation cycle, freaky.
The direction never changes. Depending upon whether the last image you looked at was left or right you see it going a certain direction because of the red and blue lines. Look at the left image, then the middle. It will go the direction the left one looks like it is going. Stare at it for 10 minutes if you wish. it will not change direction in your mind's eye. Now look at the right image for a split second and back to the middle. She's changed. Alter the times looking right or left. It never changes, just our perception it has.
Very cool optical illusion.