These paragraphs add a lot of depth and layers to the story itself. In these paragraphs, Chopin uses the setting as symbol to represent Louise's coming exaltation of freedom. She has just heard of her husband's death; in a typical storyline, you might expect her to look out her window and see stormy clouds, lightning, and thunder-all symbols of the traumatic and awful event that has just occurred, and the loneliness she will experience because of it. Instead, Chopin describes
"the tops of trees that were all aquiver with the new spring life... and countless sparrows were twittering in the eaves...There were patches of blue sky showing here and there through the clouds."
This symbolizes her coming feeling of happiness. She hasn't felt it yet, but we get a bit of foreshadowing here in the sunshiney day out her window. There is also a key description of her face, "whose lines bespoke repression and even a certain strength"; this is the only physical description of her, and hints at the fact that she felt "repressed" in her life. Before this, we knew nothing about her marriage, but here we get a clue. Also, out the window she hears "The notes of a distant song which some one was singing," which symbolizes the coming song of freedom that she herself will feel. It is still distant, like the song, but she can sense the emotion coming; she feels it there.
In all of these paragraphs, Chopin add great literary value to her story by adding symbolism, foreshadowing, and using the setting as a way to pave the way for the coming elation that Louise will feel. This definitely adds to the story's effectiveness; it makes her reaction more believable, and is a great precursor for the rest of the plot.