Not understanding details of certain questions ≠ not understanding what people are talking about. Knowledge of subject matter ≠ quality of personal character.

Not understanding details of certain questions ≠ not understanding what people are talking about. Knowledge of subject matter ≠ quality of personal character. Not privy to details, but I imagine the YC partners have observed a high # of her perceptions map out accurately. If you look, you'll find a lot of studies around character perception and related elements like body language.