Mirrors is more of an eviction of emotion from the photo. It is more intimate and your personal view of things. Where as Window is more of a realist way of looking at things. It shows that there is a world out there with different views other than your own. The Crewdson photo is a mirror and the Winogrand is a window. Crewdson is a mirror because it evokes emotion. It shows more feelings and gives a more intimate view with the viewer. From the anger on the mothers face to the shock on the daugheters face. There is body language from the half naked girl standing with her head hung low in sadness or disappointment. The Winogrand is a window because it shows things in everyday life. It doesn’t give off emotion, it’s showing you children in a drive way. It makes you think about why the kids are outside, what were they doing, it has interesting scenery in the background. Theres no just one point of focus like the Crewdson. In the Crewdson the lighting is frontlit where as the Winogrand is diffused light. The tone in the Crewdson is high key and the Winogrand is high contrast.
You have a good grasp of Szarkowski’s metaphor for photography: mirrors and windows. Another way to think of it is that the crewdson scene is staged. One would never see people acting like this. the daughter’s being in her underwear is a visual metaphor for being revealed. In the Winogrand there is nothing that you could not see if you were driving or walking down that street.