This is so ridiculous, IMO. you can find Mamdami and AOC doing the exact same pose. Doesn't mean anything, it's a natural gesture when addressing a large crowd.

The pose, as a static image, looks a little bit like someone waving their whole arm to a large crowd.

The video, by contrast, shows a man deliberately engaging in fascist salute gestures:

https://www.youtube.com/watch?v=-VfYjPzj1Xw

Pretending otherwise, that is ridiculous.