[mountn man]

Looking at the body language in the pic, my impressions are that
Putin was eagerly trying to set the dominant pose, of the overly upper hand, on the hand shake.

Trump looks like the cat who ate the canary.

Putin twisted around and looks like he's putting all his power into the handshake.

Trump looks like he nonchalantly received it. He's leaned forward, but looks like at anytime, he could yank Putin toward him.

In other words, Putin eagerly tried to play the power card. To overtly play the dominance pose, over a much larger adversary.

Trump "allowed" the clutch, but used his size and lean in, to match and neutralize Putins psychological dominance ploy. Trumps arm is on the table, requiring Putin to come to him.

Two men. Powerful men. Used to dominating their surroundings. Playing each other. Neither dominating over the other.

[Yaelle]

Yes. The “Top Cat” is the one who doesn’t care about the blusters of the lesser cat. Trump will do the “You’re the dominant one” magnanimity and turn the other guy’s hand up. It’s like saying, “You are an important man, I will give you the dominance” which means “Naturally I am dominant, it goes without saying, so I will GIVE you dominance in this display.” It’s polite and it says you already know there is no contest.

[NetAddicted]

Good interpretation. I don’t know if it’s this one, but in one photo of them shaking, they were warily examining each other.