What is the significance of the author's use of natural light in the novel, Olive, Again?

The author uses natural light to represent human connection. Strout mentions light coming through a window when light falls on a picture of Bernie Green's parents, prompting Suzanne to ask him about his childhood and religious beliefs, as well as when Olive and Cindy independently admire the beauty of the light in February. In contrast, Strout also mentions how little natural light there was in Margaret Burgesse's apartment, as she and her sister-in-law Helen proved unable or unwilling to connect in any meaningful way.