For example, in https://www.youtube.com/watch?v=rf5o5liZxnA at 35:00 you can see how an application is loaded from the network and a live chart dragged from one app to another. That isn't a one-off gimmick, it's how the OS and that version of Objective C worked.
I bought a Macbook because I was excited by this idea, but I quickly realized it was not even surface deep. I could drag some on screen elements around, but it was inconsistent at best.
But I guess there was a conflict with Raskin's idea of making everything resemble a real world equivalent (object as in "toaster app," rather than decomposed feature of "can toast") and they wanted to let third party applications do their own thing. If the whole OS (and network) was effectively the application, what's their product? Never let profound world changing innovation get in the way of a trillion dollar company, I guess.
I think of it, in my muddle headed imagineering way, this way: https://wiki.zooid.org/wiki/20120407/Raskin_vs_Engelbart
I suppose by now we would think of it all as a graph rather than OO, just add coordinates (and the required couple decades of cultural development of how they would relate) and you've got your spatial interface.