The rectangle holds its place in the room while the phone moves around it. Put a game inside and that stops being a demo: the frame becomes a porthole, and shifting the device peeks further into the world — the motion becomes an input rather than a nuisance.
The touch controls are deliberately the opposite. They are welded to the screen, full size, and never move, because your thumbs do not care where the window went.
Turn and tilt the device for a few seconds first; the ring fills as the rotation model is learned. Then switch to Play.
—
—
—
Scale is 1 − z / e.
—
—
—
Roll axis: detecting.