Why do you think Harris is not poetic?

Jerome was just eloquently describing the night in beautiful poetic prose when Harris interrupts,

Harris said: “How about when it rained?” You can never rouse Harris. There is no poetry about Harris—no wild yearning for the unattainable. Harris never “weeps, he knows not why.” If Harris’s eyes fill with tears, you can bet it is because Harris has been eating raw onions, or has put too much Worcester over his chop.