The entrance of Captain Torres into the barbershop is presented in such a way that makes it clear how dangerous a character he is and also that he feels he clearly has power over the unnamed narrator who tells us this story. When the narrator realises who it is that has just entered, he begins to "tremble" and he "hopes to conceal his emotion." Particular attention is paid to the Captain's equipment as he hangs it up:
At that moment he took off the bullet-studded belt that his gun holster dangled from. He hung it up on a wall hook and placed his military cap over it. Then he turned to me, loosening the knot of his tie, and said, "It's as hot as hell. Give me a shave." Then he sat in the chair.
This description of Captain Torres and the way he hangs up his belt reinforces his position as a dangerous, violent man, for these are the tools of his trade and the narrator, we later see, has seen first hand what kind of "work" the Captain is involved in. Note too the order in his words - the Captain clearly feels that he is a person to be obeyed and respected in this community.
It is clear that because the barber is associated with the rebels who Captain Torres is fighting against, having his enemy so close to him produces a response of fear and trembling as everything that Captain Torres does only serves to reinforce his position as a military power who is opposed implacably to the rebel movement.