Why do goalies in the NHL hold up both arms?

Patrick Roy did it. Carey Price would do it decades later to mock Roy. When a goalie's getting his *** beat, like both goalies were, and a player dumps it in on net like that, the goalie stops it and throws up his arms as a little sarcastic celebration that he actually made a save. Just something a few goalies do when they're frustrated. Usually gets some sarcastic cheers from the fans too.

It is a signal to his defenceman that there is no one chasing the puck and he has time to make a safe play. The defenceman is looking at the puck and can't see the opposition forwards behind him. This makes his job a little safer.

Yes, he's upset with something. Normally, it's the refs bad or no call.