I actually saw this in full effects near alexandra steakhouse Cupertino. It is a really impressive experience. and also surprisingly, it works for even when I w

I actually saw this in full effects near alexandra steakhouse Cupertino. It is a really impressive experience. and also surprisingly, it works for even when I was quite far away, at least like 20 meters. I wonder how the technology works. Dose it has something to do with the one way transmission?