Yeah, the theater posting a sign at the box office is not a legal posting per 23-31-235. But as I have said before, if you run into this sort of thing, engage in a discusion with the managment of the establishment. Explain to them, that the sign is not in compliance with 23-31-235, what the requirements of 23-31-235 are, and why they should not be posting signs like this anyway. I would implore concealed carry holders not to challenge an improper sign by ignoring it, but rather seeking to have to the sign removed by the apropriate authority in charge of the establishment.