4th playable class or alternate ending?

[AtrixWolfe]

There are three images of Ameli for classes, but there's also a fourth I see when looking for wallpapers online:

http://www.cheathappens.com/showwp.asp?wp=4290&n=7

When is this image shown in the game? Is there a fourth playable class? Or is this her "wedding gown"? image or something?

If you beat the game on impossible is this unlocked? :P (Hard to find info on this game T_T :()

Anyway, I also heard there is an alternate credit scene for having "no losses?" Unfortunately I had a loss when I started the game, it was the only loss I ever had but I was too lazy to reload the game so I'm unable to verify :(

Is there a video somewhere for the alternate "no loss" credits? (I can't find one).

Beating the entire game is a tall order just to see T_T There any reward for having the highest score at the end? :O

[DGDobrev]

This is not a 4th class. It's one of the wallpapers that were launched for the russian version.

There is alternate ending - it's always the same. And there is no reward for a decent high score, other than bragging rights and such.

[bukimi]

There is alternate ending - it's always the same.

Sorry for repeating question but your answer is not clear :-P
I also heard of "no loss ending credits".
So there is alternative ending (even with small difference or text "no losses") or it is always the same?