I'm not sure I understand where the gyroscope comes in.
Is he saying the warped image on the LCD changes as the iPad rotates? Does that mean two people sitting on opposite sides of the cone are seeing the same image?
My understanding from the video is that only one perspective is rendered at a time. This perspective is rendered on only one side of the cone at a time. It makes more sense when you can see the image from the iPad. Check out the video[1] at 2:37 and 3:10.