It’s not the exterior windows they are having an issue with, It’s the interior office windows. The ladies sitting inside the office have (3) 3’x5’ windows that look into the smaller room. Because of the lighting situation the mirror effect is reversed. Meaning everyone waking into that small room can see into the office, but the staff can’t see out.
I will say in our defense, we did this room at night time when the school was closed and all of the lights off except the small room we were working in so in those circumstances, the film worked great. With their current lighting situation, not so much.