He's carefully honed a lot of his mannerisms for effect. So, he couldn't have been aware that his chin up, soaking the crowd approval look, wasn't Mussolini-like.
So, like you, I've wondered why he kept on doing it? I don't think that even for the many who adored the Won, that it was a crowd-pleaser. Maybe he couldn't help himself? Or, maybe he thought he was destined for greater things?
I think the posing is actually minor to the one that is the worst, which is his totally fake “Black Accent,” aka the “Martin Luther King” accent. That’s totally a put on. No one from Hawaii would talk like that. And the only other place he lived was in Indonesia, and of course no one from Indonesia speaks like that.
I’ve only heard him drop the accent once, which was part of a response he gave to a Hawaii reporter interviewing him in Hawaii before he became a heavy hitter candidate. He caught himself quickly though and reverted into his Black Accent. He actually has a typical “haole” white accent, which would be expected if you went to Punahou and all your friends were haole (white).