Read something in Mopar Muscle Magazine that made NO sense

I got my new Mopar Muscle magazine yesterday. I came across something that did not make any sense to me. Read the text below. Since when does bore and stroke NOT
determine the engine's displacement. Correct me if I am wrong, but how is piston
height going to affect displacement??? I don't care how high or low the piston is,
cubic inch displacement = (1/2 bore) squared x 3.1416 x stroke. Am I wrong?
So what is this person talking about??
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