The featured video does not explain how it uses signals to produce which outcomes and they basically just say "we use machine learning while outputting a dance". At 07:10 it looks like the person chooses between two binary options of "sad" and "relieved". Unfortunately I doubt the person has anywhere near the real-time input to the performance as much as it is implied. Dentsu is also an advertisng agency in Japan, so it seems like this is more marketing than it is technical.

Dances by physical humans are always choreographed beforehand but live performances always show physical motion that can interrupt or change to unchoreographed movement at any time. I have a hard time believing that this person's brainwaves are mapping and producing the hologram in a specific 3D space, other than instructing it which mood preset to use at a given time.

Excluding the marketing of the ALS story, I guess I'm wondering how it's different from a Michael Jackson hologram performance where someone could adjust the sliders for mathematical functions live?