For what it's worth, this photo isn't staged or from a movie. This was back before the Roman salute was popularised by the fascists.
Although it took until the US was halfway through WWII before they decided to abandon its usage so, yeah...
You can read more about it here. Tbh I liked it better when the US was mask-off about its nationalism.
This link is almost certainly going to get caught in the censor so I'll post it in full so people can find the entry on it but I think that people underestimate just how much political pressure came from the dual forces of internal liberation movements alongside having the USSR as a viable alternative to the hegemony of liberalism.
(Relevant podcast episode: Actually Existing Socialism: How the Soviet "threat' benefitted workers in the west w/Alice Malone [58:58])
There's no small amount of disgust I have for the fact that this saying became a punchline in the US when black people were literally still being lynched. But it must have been a real knee-slapper for privileged white Americans to throw around, right?
https://en.wikipedia.org/wiki/And_you_are_lynching_Negroes or search for "and you are lynching n*groes" and check out the Wikipedia article. Then check out the entry on Emmett Till and his lynching, if you aren't familiar with the case, and tell me that punchline isn't the most cynical bullshit you've ever heard of.