I think it's one of the most important features of the design. Apple is trying to get VR/AR users out in public so that it can be a mainstream device. In the l

I think it's one of the most important features of the design. Apple is trying to get VR/AR users out in public so that it can be a mainstream device. In the long run, adding a second screen isn't that expensive, and the cameras that capture the video of your eyes already have to be inside the system to perform eye tracking. If smartphone manufacturers can make folding phones with second screens for under $1000 I think that the outward-facing display is not the lowest hanging fruit for cost reduction.