When some people become anxious, their brains shut down. It's a survival mechanism built into all of us which should only kick in during dire circumstances, but if a person is more sensitive, the brain goes blank. It doesn't happen to everyone, but it's fairly common in creative-minded people.
I think that is what happened with Megan B. That's why she seemed kind of spacey and hard to follow. Most of us didn't notice her until this episode. She probably hadn't had any negative attention on her until something was said about her dreamy face which is one of the most mild criticisms I've ever heard of a TCC, if it is a criticism at all. Megan B. seemed to take it as a criticism. When she went into the meeting with Kelli and Judy, she her anxiety level was probably through the roof, and her brain shut down.
I agree with the person who posted earlier regarding Kelli's, "We're looking for leaders" comment. They can't have 36(?) leaders. That is a dysfunctional organization. They need 36 confident people. Anxiety issues are extremely difficult for performers to overcome. It's not just overcoming publicly performing in front of millions. It's learning how to properly interpret what is and isn't criticism and how to deal with that. There is that mental toughness stuff that Jason Garrett was talking about. It's hard to do if your amygdala isn't behaving how it should.