The document discusses the differences between virtual reality (VR), augmented reality (AR), and mixed reality (MR). AR has limitations in that it cannot detect physical spaces and objects in the real world. To achieve true mixed reality, a device would need complex hardware and software to digitally map physical spaces and understand how virtual objects interact with real world walls, furniture etc. The key distinction between AR, VR and MR is that MR experiences allow users to do things not possible on traditional screens by merging real and virtual worlds.