How can the xreal one glasses be 3Dof and stay in place while this guy is moving forward and backwards in his chair?

https://us.shop.xreal.com/cdn/shop/videos/c/vp/bc70020e90a74... https://us.shop.xreal.com/cdn/shop/videos/c/vp/a2b82ae2ea714...

I appreciate its a marketing video, but this is just a lie, no?

What is the actual supported input resolution of the display? How do virtual monitors work - are they just a composite screen that needs to fit in that max input resolution, or is there some virtual viewport that is being managed by the connected device?

There is so little information about these on the website, and the few reviews I can find are basically people who got them for free (youtube is seemingly full of these right now) and clearly don't use multi-monitor setups to any great extent.