On September 15th, the North Pole would still have 24-hour sun, but it would be near the horizon. That's why it looks so sunny and the shadows are long.
I had trouble picturing what you are talking about, then I realized that I was thinking of my own bedroom door, which opens out. Most bedrooms aren't like that.
My next door neighbors are Orthodox, so <strike>they can do their Christmas shopping at the clearance sales</strike> their outside decorations stay up later than most, but they also have small children, so their tree stays up until around March. Which is nice, because I can see their tree lights from my bed.
The caption of that picture says he's a juvenile, so I guess he's like all those high school students you see who wear shorts and no coats no matter the temperature.