Oh gosh, what was her name? The Subaru impostor. ^^; The one who beat her up.. *l* There used to be a rather extensive database of screenshots from .hack//SIGN on a German website.. but it just up and disappeared one day. ;_; It had some great pics of both costumes. Blargh.
I know someone's already done the blonde-n-purple version of Subaru.. just in case MoogleQueen or anyone else hasn't seen it yet, here's one link.
Asmaria, you're right. I couldn't remember if she'd worn it beforehand or if it was just her way of showing that she was no longer the leader of the Knights. ^^
*sigh* Nobody knows where to find any pics? I'm winging it so far on this costume. Since I don't have access to those specific episodes near the end.. -.-;