Reflecting on partial reflection

I was asked a brilliant question today about why you see a lot of reflection in glass when you look from a bright place out into a dark place but not the other way round. Here's the view this evening. The lights illuminate the inside of the room so there is a lot of light heading towards the window. Some of this is reflected and we can see it. What we can't see is how much of it leaks outside. However, we can see the light from outside transmitted in. We can't see the fraction of the light from outside that hits the outside of the window and is reflected back outside. So we never see the whole picture - we see partial fractions of two different processes. The brighter one will dominate. In this case, it's the internal reflection.