My first impression was "couldn't you get the same effect as doing a video chat"? It's definitely a cool tech that seems to have come out of a sci-fi movie but for now I don't see a use for it.
In other collaborative VR technology they use the technology as a means of a better, more immersive interaction. In the demo'd games you were able to use your avatar to play games and speak with one another and it served a purpose. In this technology, the only reason to have it is so that you can see the body of the other user. I guess you could say that seeing the body of the other person can vastly change the way you interact with them. Body language is an important part of communication so there is that. You could also possibly use the tech to use sign language but then again, what's the difference between this and video chatting?
I also have a question as to why there was a need for it to be mobile? On the site it said that they choose to do it because it was seen as an engineering challenge ,which is true, however, the usefulness is still a bit foreign to me. Maybe in the future when the challenge of self driving cars is solved this could potentially be useful. It could also potentially be useful in the medical field where multiple doctors from all over the world could inspect a patient simultaneously.
Currently, the only interaction is through voice and video so maybe if there are some features like a haptic piece of equipment involved it could have various other uses.
One of the sample images is a hologram of a child so it is possible that the benefits of seeing your child and the child seeing the parent without physically being there could have positive cognitive effects on the development of said child. While we're on the topic of the range of users this is available to, we can talk about the elderly. How would they benefit from this type of technology? Maybe it is possible that a hospital bound patient could partake in family gatherings.
To be frank, I am grasping at straws finding the usefulness of this technology. Yes, it's a feat that they conquered and it's incredibly impressive but it's a push in a direction that is in unknown waters.