This could all have been avoided by some logistical changes.
If the girls hang-out room was next to the line-up area, it would be all too easy.
Contrary to that, girls at 479 have to walk up a flight of staircase on high heels and then walk the line-up.
Not easy task to do if you have to do it 50 times a day.

Another idea is a little over the top. They could do something different:

Install a big-ass TV and play either pre-recorded intros of girls or have/cut to the live feed to the girl's room where they do the line-up there.