I saw your question in the faucet thread but didn't want to hijack. Yes my windows are casement and you do not see a screen.
Got to say I loathe screens. They really reduce the amount of light that can come through. (I do not have the newer, fancier, high visibility ones.)
I live in the cold Northeast. I need screens in the Spring and Summer to keep bugs out when the windows are constantly open. During those seasons I keep screens in any window that I might want to open. Since I have lots of double casements many sets only have a screen in one side. Once we have had a hard freeze and the bugs are gone, I remove the screens from all of the public rooms to maximize light. Bedrooms always have screens.
That picture was taken in the Winter and so the screens are down.
I am sure some people think I am a little nuts, but I have a place to store the screens. Plus taking them down and putting them back up is also a good opportunity to give them a thorough cleaning. They hold onto a lot of dust and pollen- yuck!