EDIT: Oh wow, I got epic ninja'd.
@Kuro Fox
...
If they didn't use certain combinations of race/color/cutie mark over and over, I would agree with you - but where there's continuity, someone will make a story, and where there's a story, there's a soul. I would agree that most fanon has no explicit support, but really, that doesn't mean anything; if you're going to go Doylist to the extent that background ponies are randomized collections of race/color/cutie mark, then you can just as easily go Doylist to the point that Flash file called Twilight Sparkle has no significance in and of itself.
My point is this - the background ponies in each scene are randomly selected, yes, but they
represent characters that the fandom has created. Like the Flash file Twilight Sparkle represents the studious, stress-prone girl we all know and love, the file random_pny2 represents Lyra, who is a silly pony who thinks she's a human. This viewpoint may seem naive or overly Watsonian, but I like to treat characters as people - even knowing they're entirely fictional, they deserve respect like anyone else, because they move me to sympathy like anyone else. If you can share someone's laughter or tears and consider them a friend, even for only half an hour a week, I would definitely argue that there's something more to them than their framerate and render smoothness.
That's just me, though.
edited 9th Nov '11 2:18:57 PM by RedSavant