How does the author establish unity of thought and coherence in the essay?

A distinct attribute of Orwell’s style (both generally as a writer, and specifically within this essay) is his explicit or straightforward expository language. He isn’t nuanced or ambiguous in his analyses or critiques, either of character, event, idea or experience. Rather he attempts to spell out his meaning in plain terms. He presents the reader with his interpretations in clear, expository prose. This is not to say that he doesn’t deploy symbol or allegory or doesn’t try to demonstrate or illustrate by way of gestures and images. The story of the shooting of the elephant is itself a strong allegory. Yet when Orwell does make use of devices, he explains how they are working. His interpretation of events is woven through his narrative descriptions of those events.