He enumerates the parts of a tragedy and argues that they need to form a unified whole, just as the parts of a giraffe do. This notion was influential much later, when playwrights in modern Europe expanded on it to include the idea that a play should be unified in terms of time and place as well, rather than changing the setting from scene to scene. This idea doesn’t arise in Aristotle, but it’s not too far from the spirit of his Poetics.
