The preparation of fast food is not for the faint at heart.
Over here in Germany, there are no minimum wages, and Mc D.'s employees are at the lower end of what you can earn in any job. Some of them don't speak any German other than their set of prepared phrases like "Eat here or to go?" or "Do you want fried with that?"
Some of them would be lost with anything you say to them except the precoined phrases they've learned during training.
Most likely, your demand triggers a response like "Whaddayamean - fresh?", but before they could say it, they realize that this might not be a fortunate thing to say to a customer who's buying food.