I really need someone to explain to me why “ACHTUNG” vertically spinning very fast makes “HATI” in small letters, horizontally.

Is it something to do with the rolling shutter effect? Is the camera using some kind of AI image interpolation that’s getting confused? A compression artifact since too many pixels are changing too quickly for the codec to keep up? My best guess is that it’s that last one, but why does it come out as coherent text? Is there something printed on the sign that I’m not seeing when it spins slowly?