Stare at the four black dots in the center of the image for 30 - 60 seconds. Then quickly close your eyes and look at something bright (like a lamp or a window with sunlight coming through it). You should see a white círculo with an image inside it.
you don't nessasarily need to watch this all the way though but on pause it at 4:46 a floating shadow can be seen 5:09 a man/figure can be clearly seen when the camera goes back a mere segundo later the man/firgure is gone
