inb4, for people who don't get the joke:

In plenty places of the world, it's common to wave at the bus in the bus stop to make it stop so it can pick you up. We do it because 1) the driver might not see you, and 2) if the bus stop services multiple bus routes, the driver has no way to know if you're waiting for that one, or another, and stopping needlessly makes the route slower for everyone else.

Sometimes people do it by raising their arm and hand in an angle. There's no context to interpret it as a Nazi salute (unlike… say, when some fascist piece of shit is saying "my heart goes to you!", as he's greeting the voting base of another fascist, among them a lot of other fascists?), but the joke ignores that on purpose because it's a fucking joke.