This small excerpt, derives from the essay written by George Orwell, "Shooting an Elephant" and which was published in 1936.
This story narrates the experiences of an Engishman in Burma who is asked to deal with an aggressive elephant that he must get rid of by shooting. As he performs his task, the character reflects on different aspects, especially his own life and anguish by using the long and painful process gone through by the animal as he dies from the shot wound. Many critics believe that his essay by Orwell is a metaphor for how British imperialism, and especially how white people, have affected other regions and other cultures, by their tyranical acts.
In the excerpt, when the narrator talks about the word "velvet" in description of the blood that is flowing out of the shot elephant, he is making reference to the texture and visual perception of the blood and how it flows smoothly and softly from the wounded animal, making an imagery comparisson of the blood with the actual textile, which immediately leads the reader to visualize the flow.