Found this article a few days ago that lets the cast and producers reflect on the movie. All in all, very interesting to read.
How Zemeckis made the first flat screen TV.
Robert Zemeckis: You know how we had to do the flat-panel TV screen. It’s not an optical, because Michael stands in front of it. We had to get a piece of rear projection material and put it in a frame. We had a video projector film on an aperture that went through the back wall in the set. So that the projector and the frame turned together. So when Michael went and adjusted the frame, all these special effects guys turned this whole rig. We predicted that right.