If you dream of cleaning windows, (photos at the link) the allegory refers to getting a clearer view to the outside world. Sometimes, we are shortsighted because our perspective to society and the external world is limited. Sometimes, the channel through which we communicate with the outside world, is restricted by setbacks. If our intuition is aware of this, it may trigger a dream, to alert us to do something, like cleaning windows, to gain a better picture of the situation.
This painting was done based on a photo at the link of windows.