Well that was very...awkward. Never seen a dancer just stop like that because of music. She could have easily continued on dancing till they got to where she wanted to be or at least continued dancing and turned her back to the audience to make eye contact with the lead to get him to move on.
It almost makes me think it was all choreographed and when the music didn't move like she expected she didn't know what to do, very amateur reaction to me. I would expect all professional dancers, especially those who dance to live bands, to be able to react to any unexpected changes rather than just stop dancing and look lost on their face.
To me, it looks like the musicians probably added an extra bit to that section unexpectedly and she was already getting ready to catch the next part. When it didn't happen, she patiently waited and then cued them to the part she wanted. At 4 cts of 8 of the part she is on, she looks over which usually means that the next section should start, but they do at least one more count of 8 of it than she had wanted. That's my guess.
I thought it did look like Fifi and the musicians were all looking off stage at that moment which led me to wonder if something happened in the audience