If you watched the video Mark mentioned that at least 8 times. He admits having 7 cameras an two nano projectors or whatever he called them caused the frame size. He said now goals to make the frame smaller an improve the resolution an FOV.
He said just in the last year was able to put the electronics into the glasses. I have a felling Jensen was there to meet with Mark an hardware engineering over making this smaller. Both likely see how rendering high quality imaging could require power servers externally.