Just an observation during POTUS's meeting today.
Rod Rosenstein came in for the handshake from the top.
Dominator: As I wrote in my Palms and Thumbs article, someone who displays their palm downwards shows a sign of authority or superiority. Every now and again you’ll notice someone who likes to shake hands while their hand is on top and their palm is facing the ground. It is useful to know about this handshake as it may come in handy in certain situations like letting your boss feel powerful by ‘submitting’ to his dominance, or if you are apologizing about something, letting someone have their palm on top will make them feel in control of the situation.