Costume Malfuction? Raquel Torres

I was curious about the strange reaction of act Raquel near the tail end of Duck Soup. She is doing a scene with Margaret Dumont and she goes to another room to answer the phone. She appears to be holding the rather tight dress near her hip. I wondered whether she hurt her ribs or as it seems more likely, she is holding the dress so it doesn't come off.
There doesn't appear to be any lines about why she grimmaces and walks into the room
It remained odd, because if it was a dress malfunction it should have been fixed before the next shot. In the next shot she she opens the door, after a door bell gag,to the brothers running to the room. Harpo does a little dance with her, perhaps to cover up the dress problem. The whole time she is holding the dress as if it is ready to fall open. She continues to be slightly doubled over holding her ribs, or dress.
Did the dress tear? Did she hurt herself? Why did they not fix the dress is it a continuity issue? I found it weird and wondered if anyone else noticed it? She looks awkward.
It isnt the same sparkly one she is wearing in an earlier scene either.
They may have shot the scenes in sequence due to the location, but that is not always the way it works and it seems if she was coming apart at the seams they could have made a quick fix.

Anyone else notice it?