Raising the window works!
The original looks strange because of the perspective, I think. The bottoms of the "legs" of the arch both have perspective that suggests a higher camera/horizon, which is why they look a bit strange. Having the centres of the "legs" not descent so much compared to their sides should help create the look of a lower camera.
Nitpick: I don't think you need the dark line on the horizon, it looks cartoony compared to the rest of the art.