By the time one reaches adulthood it is almost reflex to give a sunny grin when someone points a camera at you. This can have unintended results.
(Prompt from CallMeGallifreya on Tumblr)
"And worse, this creature had the audacity to bare its teeth at me!"
Adjudicator Shyn'len leaned over hir desk. "Have you had much education on the habits of humans, Cogniscent P'rel?"
"That's a nervous baring of teeth. It's not a threat or a show of amusement. And further to your complaint... humans are trained from youth to bare their teeth in a smile when looking into a camera. Or anything they recognise as a camera."
Cogniscent P'rel looked enquiringly at the human in question, who nervously nodded.
"You could probably prove it with flashcards," supplied the human.
"You mistook a weapon for a camera?"
"On the plus side, it might have saved my life."
Both aliens in the court shared a mutual eye-roll and a mutter of, "Humans..."