My guess is that the window is open because of a parade. They put speakers in the windows as the floats go by. If you look closely it sort of looks like you can see a rectangular outline in the window. Just a guess.
My logical brain says it is prolly someone cleaning, but that is just to mundane an explanation for Disney!
On another note - Without having to go thru 200+ pages, does anyone know what page the pic of the Haunted Mansion, at nite, done in Topaz is on? I think it was Gdad or Evad's pic? Is there a way I can search?