Sucker coup de poing

I loved this movie, but part of it really confused me. So in the movie it shows that it is a mental home. Then it shows the girls in the uniforms attacking each other. Then it shows BabyDoll about to be labotimized. Then all of a sudden its sweet pois, pea in the chair? And all of a sudden the girls are Hookers and Showgirls? Wtf! Did BabyDoll imagine the whole thing? ou did it really happen? And if it did really happen then why did it montrer her about to be labotimized? Is she imagining it happening to her?
This part really confuses me. If toi understand it please help me out and post a comment! I would really appritiate it! Thanks