I need an exposition about the important story elements: point of view, setting, irony and symbols. Please help.

"Just Lather, That’s All" is told from a first person perspective. Specifically, it is told from the barber's point of view, meaning that the barber narrates all of the story's events. It could be argued that this offers us a limited perspective because the story is not told from the captain's point of view or from an impartial, third person perspective.
In terms of setting, the story takes place in a barber's shop somewhere in Colombia. The political situation is one of unrest because there is a conflict between the government and a group of rebels.
In terms of irony, we can find an example at the end of the story when the captain reveals that he knew about the barber's plans to kill him. This is ironic because it shows that the Barber's secret desire to kill the captain was not a secret at all.
Finally, the razor functions as a symbol of the barber's dilemma over whether or not to kill the captain. Just as the razor glides back and forth along the captain's skin, the barber's mind flips between his desire to be a good barber and his desire to become a revolutionary hero.