A word about 'with room'

Today I ordered my coffee from an unnamed mega-coffee-corporation. The woman asked me if I wanted room for cream. I said no thanks. She was a little distracted with lots of commotion behind the counter. My coffee came with room (and I probably was short changed at least an ounce or two).

So I though to myself how this unnamed mega-coffee-corporation needs to change the wording so that a double negative doesn't confuse us and I walk out of there with the maximum amount of coffee. Instead of "yes, room for cream" we should instead say "no, don't fill it to the top". See the difference.

I know, I know, total #firstworldproblems 

But there has to been some communication insight in there somewhere.