Who is the narrator, can she or he read minds, and, more importantly, can we trust her or him?
Third Person (Limited Omniscient)
The third-person narrator of "Good Country People" sees into the minds of Mrs. Hopewell and Hulga, but it presents Mrs. Freeman and Manley—the other two main characters—mostly through Mrs. Hopewell and Hulga's eyes. That's the limited part of the narrator's omniscience: It hops into some heads, but not all.
You could also say that the narrator in this story is rather judgmental, though in a constructive and fair way. Even though the focus is on Mrs. Hopewell and Hulga's negative qualities (one of which is being hypercritical of others), enough points of sympathy come through to save them from being mere caricatures.
For instance, the narrator skewers Hulga in a thousand ways—but he or she is also careful to let us know that Hulga has lots of problems which are beyond her control (think: the leg, the heart condition). While the narrator doesn't suggest that these problems are excuses for bad behavior, they do admit that these things isolate Hulga in a variety of ways.
Here's the big reason this good-with-the-bad narration style matters: In a story in which every character is not to be taken at their word, it's helpful to have a narrator, at least, who can be. And by painting a complex picture of the characters, we feel like we can trust the narrator.