[paul.fr]

Travelling on the train the other day, i was looking through the window and noticed that i saw a double reflection of the passengers and the interior of the train.

the window, as far as i could tell, was a single pane of glass. why would this produce a double reflection? was the angle i was looking from, a factor?

Paul

[Soul Surfer]

You do get two reflections from a single pane of glass one from the front surface and one from the rear although thy are usually so close together that you don't notice.  Looking at the glass from a glancing angle would maximise the separation of the two images.