In a way, the big three, in their social interactions, show off the three classical forms of greek debate;
Diana, as we saw, represents, Logos, or arguing via logic; she presents a sound and reasonable reason why that guy should not do what he's about to do, and she gets results by appealing to his sense of reason.
Superman represents Ethos, or arguing through morality; when he talks to villains (like Parasite in "welcome to the working week", which by the way someone should totally post as part of this perfect moment, especially the end where they give a verbal smackdown to the big bad, but I digress), he talks to them like human beings, he see's beyond their masks to the people they are underneath, and they respond to that.
Batman represents Pathos, or arguing through emotion, in that he uses emotion to subdue his foes (IE: he scares the ever loving shit out of them).
Sorry for rambling, this all sounded a lot cooler in my head.