Even if the bakery employee yelled "What?" at me, I would not hear snark in that. I would probably hear rude, but not snark. I would also be a little less surprised if it was a very busy place and the employee was visibly harried by the commotion. Or if I was just in any store in NYC.

There's a difference between terse and to the point vs being rude. It's not the terse response's fault the recipient cannot tell the difference.

Also, are we using snark as a synonym for rude nowadays? I'm going to need to update my definitions as I was always understanding snark to be sarcasm. I just want to be using the same words as everyone else on the internet so I don't offend. (that was snark).

Edit: actually, if I went to a store and someone asked "how can I help you today dear gentleperson?", I would immediately assume they themselves were being snarky. That's like saying "bless your heart". It's just dripping with snark.