This reminds me of the original patents that Magic Leap had, which involved pumping light through a single optical fiber that was wiggled by piezoelectrics into a spiral to project light (https://kguttag.com/2018/01/06/magic-leap-fiber-scanning-dis...).
Seems what it is, but with a "waveguide" instead of an "optical fiber" wiggling about. Seems like a sneaky use of the word "projection" though, since the "surface" the image is "projected" is just what the flopping waveguide head traces, with no projection extending beyond the end of the waveguide.