There’s a ton of resources out there for those of you who want to make POVs including my own golf club POV I made couple years back. Check out this simple wave LED POV display, the author offered some free code so you can bypass the programming part. (or hack it for your own messages)
If you think this device looks similar you would be right, he took the display from the spinning display and mounted a 4 X AA battery holder to it, mounted a small circuit board onto the new device and made a switch that detected motion to the top. If you would like to make your own Csaba has made the code available.