The bottles are REAL GLASS, not the newer plastic bottles! You and a spectator each put an upright bottle in a heavy board tube. From that point on, no matter how the tube/bottles are flipped top to bottom, the two bottles do not match up when the covers are listed. If your bottle is upright, the spectator's is upside down ... and vice-versa. The standard presentation is that your bottle is always "correct" and the spectator's bottle is always "wrong". This is done with three turnovers and your use of the special gimmick.