// this is what the page does when you enter it
function room(level, size) {
  if (level === 0) return;        // base case
  drawVideo(size);               // the room
  const mirror = size * 0.58;  // a smaller room
  turn(level * 7);
  room(level - 1, mirror);       // ...in the mirror
}
// move your pointer: left = shallow, right = deep