What message can be received from "Shooting an Elephant"?
Concerning your question about "Shooting An Elephant," I don't know if "received" is the correct way to think about the ideas presented in the essay. If one is precise, a main idea is presented in the essay. You can also think in terms of thesis.
The main idea of the essay is something like:
The imperialist power is transformed and corrupted by its imperialism.
The colonized are not the only ones damaged by colonization.
By his/her position of power, an imperialist is morally corrupted.
The speaker is made to do things he would not otherwise do. He not only is forced to kill the elephant needlessly, but because of the abuse he suffers at the hands of the locals, he actually develops prejudice and hatred against them. Because he must maintain his position of authority, he must behave as he's expected to. Because he is in an illigitimate position of authority, he is mistreated by those he is in charge of, and he responds naturally.
"Shooting an Elephant" by George Orwell is completely about Ruler and the Ruled.Living in the illusion of the theory that those who belong to the Ruler class can do anything if wanted(imagined by those who are ruled,in this case the natives of Moulmein, in Lower Burma), forced the author to commit the action of killing the elephant who was already out of the attack of "must".The conscious of the author failed and by this he realized the futility of the white man's dominion in the East which is actually a hollow myth with no substance at all.
It is quite a challenge to write this answer in 3 sentences. You can short it if you want.