It is a hologram projector made with a thin plastic sheet and your smartphone! Seriously, it is so simple to do!

It proposes that the universe is a three-dimensional image projected off a two-dimensional surface, much like a hologram emerges from a sheet of photographic film. Known as the holographic principle, ...

Put a projector behind this thin sheet of vapor, and you have a display ... but it’s still a very cool build for a custom holographic display. BTW, yes, we know this isn’t a hologram.