But I guess that would make the timing part be obvious and kind of ruin the "fun" of the story. Though I fully agree, the difference between "front of store" and "back of store" icecream couldn't be that much and also doesn't make much sense.

Or I could imagine something like a Sonic drive-through, where you often pull up in to a slot and turn off your car, but only until your order gets brought to you by a bellhop:

- works when I order a burger (burger takes a few minutes to cook)

- doesn't work when I order a hot dog (those are hot and ready to go)

or something like, works when I order a chili dog (because they have to heat up the chili)