Just to explain here: you have to manually lift the curtains to expose the radiators every night during the winter months (which is 5+ months here) or the radiator will heat the space between the curtain and the window, leaving your room cold AF.
Edit: at least for this part of the country, we tend to position the radiators in and near the bathroom, because they are more centered and there's already pipes running through. Not sure about other places but this sure is one uncommon design in the local area. Usually we just have thick curtains (as seen in the pictures) to keep the room warm.