There's a video that's quite convincing: https://youtu.be/K0Xio5yo_x8 https://youtu.be/K0Xio5yo_x8 It inverts the second image and passes the first and third i

There's a video that's quite convincing: https://youtu.be/K0Xio5yo_x8 https://youtu.be/K0Xio5yo_x8 It inverts the second image and passes the first and third images under it, and when there is a complete overlap the combined images make a nearly perfectly gray rectangle, showing that they cancel out.