I believe the custom of clapping at one’s audience was originally intended as a salute to the audience. No idea what Trump thinks he’s doing when he claps. I am fairly certain he is unaware that the raised fist is common among leftists of many persuasions. Unless…maybe he really is a Russian spy, but old-school Commie?
That really illustrates his tiny hands. And his horrible dance moves. Elaine looks like a Solid Gold dancer compared to him.
I think this is what he believes he is doing because while he is clapping, he exaggeratedly mouths “THANK YOU” and then points to his adoring cult members.
He’s actually a double-secret agent for BLM whose mission it was to expose and destroy the Republican Party from within, and that’s his secret BLM salute.
Which BLM?
I sort of like the idea of BLM as a sleepy Federal bureaucracy whose legit mission is plagued by run-ins with RW rifle-toting nutz. Now they’ve gone rogue themselves, having decided they’d had enough of the nutz and now they want to pwn the cons once and for all. So they hire Trump to blow up the RW movement from within.
This has given me hope…
Here’s one example of his silly little fists: Trump summons dregs of Republicanism for 'announcement' that he is running in 2024
MY EYES!!! Arg curse you. 
No seriously.
He does that when he dances. He probably thinks it makes him look cool.
For I am the largest failure in all the land!!!1!
His fist thing vaguely reminds me of the half hearted Nazi salute you would see sometimes on Hogan’s Heroes. Usually by Klink after he says “Yes, yes, Heil Hitler.”
Unfortunately for us, his audience thinks everything he does looks cool. To everyone else he looks like he only has a vague idea of what dancing is.