You can see the person's finger (or the CastAR wand's tip). I imagine the rendering engine will show the same thing in the same place relative to the real world

You can see the person's finger (or the CastAR wand's tip). I imagine the rendering engine will show the same thing in the same place relative to the real world for both users. It doesn't have to, in the case of a game where you each have your own point of view, but it could if the game works well that way.