It's probably an optimal place for that kind of lighting fixture, but it looked weird for two (conjoined) reasons:
- Its style was the classic "coach lantern," wider at the top than the bottom, and
- It was--like I said--above the door rather than beside it.
Yet a 21st century light bulb is shielded from the elements with a relatively inefficient (from the standpoint of surface area to volume ratio) 18th century design...and is expected to be placed at a level easily accessible for the servants to light or snuff out on a daily basis. Because that's what "normal" is supposed to look like, dangitalready.
That, gentle reader, is why thinking outside that benighted box is just so bloody difficult: You have to know that the box is there in the first place. There's just so very much "normal" to go around, and the "weirdos" who install porch lights in places that call "normal" into question aren't too thick on the ground.