Notice that Genji refers to the Rokujō Lady as jealous and demanding; this suggests that the Rokujō Lady may have more power than Genji or the narrator has given her credit for up to this point, as the novel has already made it very clear that female jealousy is one of the most powerful things within the logic of the novel. The banter between the Lady of the Evening Faces and Genji shows that for Genji, this is all just a fun jaunt. The lady's fear, however, shows that this is far more terrifying for her and she's aware that she has little power in this relationship.