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? (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