Doesnt matter.. if he drapes you while you have an OWB holster or an IWB/Virginia Tuck.. and it covers it.. you are concealed. Which holster does this guy have?
Back on topic... it would make for a very interesting court case. The carrier could argue that he or she (if women go to barbers?) did not conceal it, but the barber did, and that the barber certainly would have known it was there before they covered it up, as would any other customers or barbers in the shop when the carrier first came in.
The only people who could really argue that it was "concealed from them" would be anyone who came into the shop subsequent to the act of covering at the beginning of the haircut.
In this context, it very much lines up with the "sitting against the wall in a booth" idea, which we have almost universally argued is "not concealed", even though it is equally out of sight.
The question, "Which holster does this guy have?" is equally unanswerable for the carrier sitting in a booth against the wall. Under normal circumstances, both carriers would resume an "unconcealed" stance as soon as they got up from the chair in which they were sitting. I can't ever remember getting out of a barber's chair with the cover still on.
As always, nobody wants to be the test case, but it would be a very interesting case indeed.
TFred