What I find very cool is that it's extracting scenes from the running game and then projecting them into the VR space, allowing the scenes to be panned/rotated in a way that isn't possible in the original game.
If you haven't watched the video, check it out; my assumption from just reading explanations here was that it was just projecting a facade of the emulated device and its normal rendering of the game into VR.
I actually originally assumed this was entirely done by some AI interpretation of the original 2D projection of the game scene, conjuring the entire new 3D scene. But of course, just extracting the vertex data from the emulator is way better.
If you haven't watched the video, check it out; my assumption from just reading explanations here was that it was just projecting a facade of the emulated device and its normal rendering of the game into VR.