You know I can’t even really be mad that this scene doesn’t manage to pass the Bechdel Test because of how beautifully it highlights everything that Elementary has done in granting women agency within narrative space to significantly impact the course of the plot and drive things forward. This scene has several big duties to pull and it does them all quite beautifully.
First, it helps to highlight what I’ve seen other people mention before, that Elementary does a very good job of balancing danger to Joan without dismissing her responses. In this scene the peril to Joan is evident. She is plucked off the streets and brought to a restaurant to converse with someone she knows to be a ruthless murderer and yet there is no hysterics to tug at the audiences fear responses by placing Joan in a “torture porn” setting where she is restrained or the light is dim and she ultimately fulfills the narrative role of damsel in distress. The danger is real and the audience feels that, but we don’t have the pandering payoff of seeing Joan tied to a chair and at someone’s mercy. Joan may be in peril, but she is not forced to play into the expectations of what that should look like.
Second, it highlights Joan’s extreme courage. This is the first time she has been face to face with the woman that she had known as Irene knowing that she is in fact speaking to someone who had orchestrated probably hundreds of deaths. The very first line of this scene is Moriarty’s observation is that Joan is not afraid of her. Joan’s rebuttal, that she is to angry to be scared, is both a testament to her control and her protectiveness of Sherlock. Joan is beautifully unwavering in this scene.
Third, it sets up Moriarty’s downfall by highlighting the advantage that Joan has in this pas de trois, her interpersonal intelligence. Both Moriarty and Sherlock have a certain degree of external emotional intelligence, they can see reactions in others that they can consciously interpret, but they have a poor grasp of their own emotions and expressions because neither are very used to deducing inwardly. (Though one can argue that Sherlock, through Joan’s interventions, is making progress.) To Joan it must have been almost painfully obvious, maybe even too obvious causing her to second guess, that Moriarty is in love with Sherlock and that is her weakness. To the audience, it seems pretty clear as well. Joan is pulled off the street and threatened in a crowded restaurant with assassination and one of the few real questions (a question that is quite obviously dodged) is if Joan wants to have sex with Sherlock. If that doesn’t smack of insecure jealousy, I don’t know what does. But Moriarty has completely failed to see that she’s tipped her hand because the recognition of her own responses is clouded by how distant she is from her own emotions. She doesn’t see her jealousy because she doesn’t feel her own emotions, merely observes them. Joan can recognize this situation for what it is because she is in touch with her emotions and those of others, including those around her who are least in touch with theirs. In a very beautiful way, the very thing for which Sherlock and Moriarty might dismiss Joan, sentimentality, is what very much saves the day.