Yes, you are perfectly right, I just saw part of it, missing completely the point.

I think it would be much easier to just vacuum all hairs (or use electrostatic as suggested), so to have all hairs perpendicular to the skull, and then cut them out like you would cut your garden. If, and only if, hairs grow uniformly then by cutting 1cm of all hairs you will get the same (expensive, human made) cut you had X time ago :)

I scrolled fast the video for an image of him with all hair up :) I did not see it and I superficially judged it.