Board Thread:Speculation House/@comment-25266931-20151209055514/@comment-4010415-20151209164730

Basically,


 * Yang has seen a photo of Raven before Volume 3, considering she actually has a photo of Raven on her Scroll, which she showed to Junior in the Yellow Trailer.


 * Therefore, Yang knows basically what Raven looks like. It's unknown how old the photo she has is, but she knows the gist of what Raven looks like.


 * When she caught a glimpse of Raven leaving the train, she recognized the outfit and the hair, maybe even the weapon.


 * The last we saw of Yang before the credits, she said she was going to sleep.


 * The music and visual effects in the after credits scene is very dream-like suggesting, the whole thing was just a dream.