What I see in this photograph is 3 floors of a city house. The bottom floor is not the ground floor, because is has a balcony. This is confirmed by the image showing how the perspective was straighten, the floor with the large balcony is actually the first floor (or second floor in US usage).
I see a gray drain pipe running down the full length of the picture on the left and a second salmon pipe next to it (which would mean that there is a flat under the roof). To the left of the center row of windows, there is another down pipe, salmon on the top and gray down below. That pipe connects:
-the room of the top left window at floor height
-the room of the middle left window at floor height
-the room of the center window at ceiling height via the white rectangle under discussion. There is a diagonal line coming from the right of that rectangle via a hole in the wall, to a vertical salmon line to the right of the center window, then a horizontal salmon line going to the right of the balcony, then a gray pipe going down and then around the balcony railing to the left of the balcony.
I see a short length of line coming from the right-hand side of that rectangle into the wall, crossing the pipe. This could be a small length of electric wire.
There is a hook in the wall without apparent function to the right of the center balcony.
If the rectangle is a light, opening the window shutter will obstruct it.
There is a large collection of wires coming into the wall under the top left window. There is a thin cable hanging from the middle right window.
On the bottom balcony, I see an AC condenser. It appears to sit next to a rectangular contraption similar to the top one and then to a much longer vertical rectangular line, reaching again to the top of the room. There is no apparent other evacuation line out of this condenser (but it could run under the balcony). There is a length of cable left of the condenser leading to a hole in the wall. From the wall, there is another length of cable running under the bottom center window to the left of the balcony. We cannot see that balcony part, but there is some white showing on the top, so that second line may connect to a second condenser.
The shutters are of different colours and state of maintenance, so it is unlikely that the house is owned by a single person. A flat is for sale on the top floor.
