Create a two-way video communication method between Quest (could be Rift too) and Messenger (remote) OR the companion app (local)...
The purpose would be to make VR more social / less isolated - in particular in relation to people sharing the same local space. For example, being able to play at home while also being able to chat with one's family.
In the HMD one should get a HUD-like floating monitor popup with the video chat window, in a way that's not too intrusive to the VR activity itself.
In the non-VR client (which can be the Oculus companion app for local use or the Messenger app for remote communication), one should see a Tony Stark in Iron Man-like view of an Oculus Avatar, animated in real-time with face motions just like in Venues/Horizon. For extra sci-fi effect, maybe there can even be dashboard/UI elements surrounding the face, that are custom-made per game?
For cheap rendering cost, the non-VR client doesn't need to include a "camera viewpoint" background from the VR app being played - but instead the video chat mode could be an extra feature as a pop-up window in the regular casting/streaming view, so the outside person can also get a sense of what's happening in VR.
Of course this could be expanded to also work as a VR-to-VR video chat feature! Maybe even for multiple users, Zoom-style, to replace/complement the existing Party function.