You Order a Salad, with Dressing on the Side, from a Tall

Short Answer

You order a salad, with dressing on the side, from a tall waiter in a white shirt. Several minutes later, a short waiter in a light blue shirt brings you a salad with dressing on top and you say angrily, "I specifically asked you to put the dressing on the side!" In confusing the two waiters, you have demonstrated _______.