Point of view refers to the perspective that the narrator will use to tell the story. In the case of Nathaniel Hawthorne's The Scarlet Letter, the unnamed and ambiguous narrator uses a third person omniscient and subjective perspective.
A third-person omniscient narrative is one in which the narrator tells the story of each character, demonstrating that it is the narrator who possesses all the information about everything...even more so information than the characters have of themselves or of the story, as a whole.
However, in The Scarlet Letter the reader can detect partiality from the narrator. It is easy to sense, in the tone and atmosphere in which the characters of Dimmesdale and Hester are shown, that the narrator tells their particularly unfortunate stories differently and with pity. Similarly, the reader can sense the terror and disdain that is felt each time the character of Chillingworth is present. For these reasons, the point of view in The Scarlet Letter is not only third person omniscient, but also subjective. This means that the narrator also analyzes and brings in some of his own sentiment into the narrative.
Poor, miserable man! what right had infirmity like his to burden itself with crime? Crime is for the iron-nerved, who have their choice either to endure it, or, if it press too hard, to exert their fierce and savage strength for a good purpose, and fling it off at once!
This quote is a good example of how the narrator becomes involved in Dimmesdale's sadness and voices his (the narrator's) own opinion about how he feels about him. This is what makes the narrative so heart-felt. After all, the narrator is not merely a story-teller but seemingly a clear witness of the terrible situation that befalls the relationship between Dimmesdale and Hester.