1. If Barbara had performed this gorgeous number at her full force vocally, she would not have been able to convey as much sifting out of the thoughts of her heart. It would have lacked the subtle attraction and vulnerability she feels about her attraction to the character of Nick. She obviously struggled with insecurities and inexperience, which is revealed not only by the dialogue, but her actions as she performs the song...we gain a gorgeous glimpse into her introspection, as a woman, not as a performer, through her interpretation and action, portraying Fanny.
2. She is nervously