How does the tone play a part in "Shooting an Elephant"?

Tone, the expression of the author's attitude, plays an integral part in Orwell's essay "Shooting an Elephant"; his attitude toward his subject matter is a reflection of his feelings as a policeman.
In his analysis of the incident that begins with his call to attend to a frenzied elephant that is "ravaging the bazaar," Orwell expresses a rather sardonic and bitter tone because he realizes there is no diplomatic way to resolve this dilemma since it is closely tied to the very nature of imperialism. Rational human intercourse is impossible; he must demonstrate that he is one of the rulers.
In his essay, George Orwell perceives the incident as indicative of the conundrum of imperialism. Imperialism demands a particular posture on the part of the rulers as well as on the side of those who are ruled. After officer Orwell responds to the call about the ravaging elephant, he discovers a coolie's body crushed by the elephant. However, when Orwell comes upon the elephant, who has calmed down and is peacefully grazing, he observes, "I knew with perfect certainty that I ought not to shoot him." Moreover, he has no desire to shoot the elephant. However, when he "look[s] at the sea of yellow faces" watching him," he knows that he will shoot it. 

And it was at this moment, as I stood there with the rifle in my hand, that I first grasped the hollowness, the futility of the white man's dominion in the East.

Although he is an officer of the ruling government, Orwell feels like a puppet forced to do the bidding of "the sea of the natives." They "expect" him to shoot the massive animal because he has brought a rifle with him. Because of this expectation from the natives, Orwell finds himself loathing them; they force him as an officer of the government to appear resolute, "to know his own mind and do definite things." If he does not shoot the massive animal, Orwell knows that he will appear weak and indecisive. Also, if anything were to go wrong as he approaches the elephant, the natives "would see me pursued, caught, trampled on. . . . And if that happened it was quite possible that some of them would laugh." While he does the right thing legally because the elephant has killed a man, Orwell knows that he shoots this elephant who has quieted down and is grazing peacefully "solely to avoid looking like a fool," and his action causes him to become cynical.