I was happy to see that people were excited by the portion of the Apple Vision Pro demonstration where the dinosaur walks through the screen and into the living room because I knew you could do that today with iPhones and iPads.
Last weekend I experimented with combining multiple animations from Mixamo.com in Blender. This weekend I added a portal - a door through which you can see into a 3D world and characters can walk through that door into our world.
Here is a proof of concept video:
Here is a screenshot from the WWDC Keynote showing the dinosaur walking out of the portal and into a living room: