What was that Unity XR demo?

A few months ago there was a short clip just before an VR event showing I think Adam walking towards the camera in VR, then stepping through a portal into what seemed to be the venue in reality, but AR (probably).

I've been looking near and far but can't find it anymore. It might have been posted quite subtly somewhere deep in the bowels of the Unity site or on Twitter.

Can you find it?