I just found this animation and thought it was particularly intelligent, especially the folding animation to show that they went for a totally internally reflected path to shave even more thickness on the optics.

It does seem that the light efficiency has been increased over the traditional birdbath too since the light gets halved twice (so only 25% makes it to the eye). Below are some of the paths the light will take

Since the whole system is reflective, there's no opportunity chromatic abberations either.

Looking at the actual device, it kinda seems like something that might be theoretically possible to print on the #SecSavr Suspense [gd0105]:

But that sounds like having to print stainless steel and glass (or some high temp transparent material due to the sintering of stainless steel) in the same print, along with polishing gear in the Brick of Innovation to get this kind of finish: