Little Too (Chihuahua) in 3D!
This is called Wiggle Stereoscopy.
With most stereographic images, one eye sees one image while the other eye sees another image. The two together create the illusion of depth, as it simulates how we see. Normally, each eye sees a slightly different perspective, which gives us our depth perception. Stereography tries to replicate that.
With wiggle stereoscopy, the two images are animated. This allows some people to see the illusion of depth.
Of course, it would be difficult to watch a movie like this. 
Dizzying too, probably.
One advantage is that, unlike most methods of stereoscopy, the 3D illusion can be seen with just one eye in wiggle stereoscopy.
super cool!