system
A chat on subreddit /r/me_irl
human
Oh shit I AM Canadian. I read it as “go ahead. I’ll wait.”
gpt
Also Canadian here - the two gestures are very similar, but the "you first" gesture is more of a side-to-side wave, whereas the "what the actual fuck are you doing" gesture is up-down and the hand is more tilted (and also sometimes involves two hands).  
At least in my experience...