A pix and three questions

I really like this picture.  It's the window in the apartment we rented in Paris a couple of summers ago.  I've used it in a couple of art pieces.  So, here are the three questions:
1.  What is it about windows and doorways that are so appealing?
2.  What would this look like done in pastels?
3.  What journaling would I add?

Thanks for your feedback on my clothesline piece, which led me to think these thoughts . . .