No quantum spin effects
When the image is a silhouette, it could represent a clockwise-turning woman, seen from above, or an anti-clockwise-turning woman, seen from below. If your brain assumes it is seeing the silhouette from above, then you see it as clockwise-turning.
I could also flip the direction of rotation by concentrating. I tried lowering my chair to see if my angle of view to the monitor would modify my perception, but the result was inconclusive. I did start hearing some cheesy music and see a pole...