I can control the direction. It kind of feels similar to 3D stereograms where the image just kind of 'snaps' into place, but in this case, she starts spinning the other direction. Kind of fun and quirky, and you really have to do it on purpose.
To provide a corroborating perspective on this, I learned to control this too, but it took a lot of practice to do it, and even now it's not 100% immediately effective for me.
Same here, not 100%. I actually just tried it on the spinning dancer, and the more I practiced, the better I got, but definitely not 100%. I bet I could get there with enough practice though.
