The main point, the theme, of "Shooting an Elephant" is to expose the conflict between the law and one's moral conscience as this pertains to British imperialism specifically, but by extension any imperialism. Orwell makes his point in two major ways. First comes the decision of the narrator British police officer in Burma as to whether to shoot the rogue elephant or not. The very definition of rogue (having become savage and unpredictable) means that some sort of action is required in order to protect the people.
The narrator doesn't personally want to shoot the elephant and cause it to suffer a painful death but because of his position as the representative of British law he must and he does. Later he is torn with terrible emotions of pity at the sight of the elephant's death. He is also shown the body of a man who was trampled to death by the rogue elephant, a body in a sacrificial crucifixion position. As a result, the narrator has an epiphany (spiritual awakening) and realizes that even when acting within the law, the law can be at conflict with moral conscience and in the case of British imperialism, law does oppose conscience.
George Orwell drew upon his experiences as a British colonial official stationed in Burma and in India for writing "Shooting an Elephant." By the time he wrote this, he had already established a reputation for writing from a social conscience because of his nonfiction work Down and Out in London and Paris (1933) and novel Burmese Days (1934). Critics are divided as to whether "Shooting an Elephant is an essay or a short story.