Mary: Peter! What are you thinking? We don’t have any drinks yet. Are you going to get us some drinks or we’re going to be here the whole day without them?
Peter: All right! I’ll get them.
Peter starts for the counter.
What did Peter do after Mary’s complaint?
He started for the counter to get the drinks.
I meant you made an amendment relying on some grammar rule.
My take on it: it’s a case of interrogative sentence being declarative in fact, and thus used to display emotions (irritation/sarcasm/impatience) which I believe suits the situation. What she does, she doesn’t put two questions allowing him to choose between the two alternatives—she prompts him to act really.