good point you make.
sometimes i wonder with authors, they like to use things that seem symbolic, or are so slightly, but not worked out completely or in a perfect metaphor.
windows seem to symbolize the transparency of the inner person and the outside world, a fitting metaphor for the human choice for honesty. also a window is a two-way street, a positive and negative, the meeting of self and other, interior is shifted with exterior, so that both are unclear, the crossroad where one's downward path is reverse of another's upward. just as illumination, light, (truth) etc. should come from the light outside, through the window, to reveal the interior to those inside, it is also the window that reveals the interior to those outside, turning the house (domestic life, bourgeois etc.) into a cage or menagerie, whose only end is pitiful destruction (such as the gray scene with the cars). The couple who had their windows filled in with bricks symbolize a close minded people, who have no care for the exterior of themselves, only are fixed on their interior being, on a created world untouched and unchanged by the outside. when their daughter left outside the walls, she became in effect dead. The lady who solves her problem, Anita, is interesting case because she is talking about her house, or what was her house, and is in a story a piece or model during a sexual act, concentrating on sitting a certain way, so in that sense a showpiece.