He is nervously laughing tbh.
Yea Jones is so cool and confident that he had to say 'you suck' rather then just walk and say nothing. Staredowns the same - not confronting eye-to-eye is not confidence. Same with the previous one when DC made a boxing gesture all what Jon did was shake his body and stick his tongue - wtf was that? - cool and collected confident champion?
DC is more emotional but both gets something from their opponents