The repetition made them look strange. They didn't look like windows anymore. The experience was similar to saying a word over and over-- eventually it stops making sense. It becomes objectified. It is no longer what you thought it was, somehow it warped into something else.
Profound or profoundly obvious, I see windows like this. Windows are made to see out of. But they're also made to block the outside view in or the inside view out. They are selectively useful. Windows also allow air in but they can also stop it from coming in. Again selectively. Your relationship to the window changes depending on where you stand. Inside or outside, to share or to block. What would a house be without windows?
At the moment I see darkness and light out the window, clear and overcast with the brightness of white snow. There is a lack of green and deep blue skies. There is no humidity in the cool air that blows in. But then I can just shut the window and turn on a light.