"Ah," Laura says, and frowns a little, considering. "It depends. Sometimes they're on walls, and then they look like big black boxes with a sort of handle loose on a hook, connected to the box by a cord. But sometimes they're smaller, and on desks, and then it still looks like a handle, but it's resting more on a stand."
Well, it's still the thirties, after all. Push button phones do not exist.