It's the latter I expect. A meal should mean +fries&drink, regardless if that is on the menu. It seems intuitive and obvious enough to me. But I have been known to have overly high expectations of others. I will lower my expectations accordingly.
It's not even a matter of high or low expectations. It's sideways. There's a specific concept you've invented and you want everyone to participate in it. It's more of a hope than an expectation.