NetRunner, How are you confused about the fact that this silhouette was generated by a 3d model of a dancer spinning? The shadow below her gives this fact away. It would be very difficult to create an accompanying shadow to the silhouette if not using a 3d model. They simply did not light the model, and this is what produces the illusory effect. They did light the rest of the environment, however, to make it clear which way she is moving.

MarineGunrock, you have it backwards. Do not pay close attention to the model. Instead, follow the shadow underneath the dancer, which is lit, and therefore gives away depth information. When the shadow of the raised foot appears, that foot must be behind the dancer. If the shadow appeared when the dancer's raised foot was in front, then the light would be in front of the dancer, so the shadow would be behind her, and would not be visible in the image at all.

The real mystery is why this image appears to spin clockwise at all. I can see it, but I don't know how.