[![enter image description here](https://i.stack.imgur.com/ujdhI.png)](https://i.stack.imgur.com/ujdhI.png)

I have a question regarding photons nature. Let's say I have a single source of light - regular bulb and the observer - in the same room. 

The observer looks through a glass window (normal glass window-nothing special about it) and sees his reflection, but some of the light is passing through the window.

Now I put a second window - as presented on the attached photo. Will the second window reflect some of the light back to the observer, or it will pass 100% of the light forward?

This may be pretty basic but this question sparked a discussion and there where no definitive answer.