Yes I think I actually spotted this in their video demo where you will notice one of the displays looks way way way better than the rest of them. That would be a projector one.
It is considerably easier to achieve sync and high framerates with LED i would expect. There are also some dedicated chips coming to the market to drive stuff like those POV video signs that are now available on aliexpress for a song.
If I implied this was a singular product, I apologize. There are quite literally hundreds. Searching for "Hologram Fan" will pull up the type I am specifically referring to as being a current fad, but the number of other LED POV display stuff available on aliexpress is immense.
"the Voxon VX1, a device that uses ultra-high-speed video projection to display slices of a 3D scene onto a reciprocating 2D glass plane"
https://www.youtube.com/watch?v=CCuybyAO8fs