Hmmmmm, I find your use of the word "landscape" interesting. I am guessing that you are referring to the difference in the "landscape" of a medical office vs. the "landscape" of homes in need of cleaning. If this isn't the case, please feel free to repost your question.
In short, there was dignity in the landscape of the medical office. That is where the narrator's mother used to work. It was an office job, one that allowed pride in one's work. According to the narrator, there is pride in that type of work, ... the same type of pride that he will achieve when finishing law school.
The narrator considers a lack of dignity in the job of cleaning houses, which is the job that the narrator's mother decides to pursue in order to pay off her son's law school educational fees. This is why the story is called "On Her Knees." Her dignity is further devalued when she is accused of stealing a pair of earrings (which are subsequently found when vacuuming under the bed). This affects the narrator negatively in that he can't even "lower himself" in order to help her; therefore, when he does, he does so resentfully. (It is the narrator who vacuums under the bed and finds the earrings!
The narrator finally learns just how dignified his mother really is when she refuses payment for cleaning the house feeling that the loss of the earrings was her own mistake. The irony is that it is the narrator who "hides" the earrings in the cat box in order to have his mother stop this menial job. The narrator realizes his error. The story ends well:
It seemed that the very light of day was pouring out through her limbs. I had my breath back.