Norwegian windows

As my new windows are completely naked - no curtains, no plants, no decorations etc. - I have been looking at other people's windows. How does a Norwegian window look like?
If you live on the first floor on a busy street, you may need more protection for privacy, though even here there is much openness in the window treatments. you can often look straight into the apartment.
The curtains are usually of some light color and are often caught on the sides to make the typical triangle opening. Some prefer two curtain lengths hanging straight down from the sides. Very many put plants in the windows - in my imagination both for making life inside a little more private, but also because people enjoy plants growing, particularly in the winter.
Some put a lamp hanging down in the middle. Some add to standing lamps.
Last part, some decorations like small sculptures.

Where I lived before in Moss, there were a few houses where the curtains were always drawn. There weren't really curtains, but actually big pieces of cloth completely covering the windows. This intrigued me. Who were hiding behind the curtains? I still don't know for sure.
The most likely explanation:
Persons from countries without the tradition of Norwegian window treatments.
My theory is that Norwegian criminals hiding their activities would know that such covered windows would draw unwanted attention to their apartments, because it is so unusual.
Mystery....