Liberals would liken him to an "evil Chinese dictator" stereotype like they try to pretend him and Putin are "evil Stalin" stereotypes. Probably see memes of Trump as Mao, and a revival of anti-CPC discourse, but applied to Trump as "ruining America" or "selling us how to foreign powers" or "wanting to be authoritarian".
In all the ways that matter, nothing significant. He's a duplicitous bastard who can't be trusted, so he may talk nice about Xi for a week before going "he's not giving us Taiwan even though I asked nicely, what a tyrant" and going right back to anti-China warhawking. China certainly isn't going to do anything for him just because he showed up to a parade. No other country is going to change their views because of it. US rivals know the US is two-faced and vile, and Trump is the personification of it. US allies hate him for saying the quiet part out loud but jump when the US says "frog" anyway.