Yeah yeah, how original, doing Hermione for a Yule Ball themed painting. I know. But I immediatly thought of her and Krum, and it felt right to do it. At first it was a dancing scene though, but when I watched the clip, I also saw this, and I thought it was so beautiful, and Hermione is so happy.
Because I really think the Yule Ball is Hermione's night, she looks beautiful, she's with Krum which is probably her first love, the first person to appreciate her in that way. I can imagine that she's very happy here, until Ron ruins it that is.(but we all know why he does that, so we forgive him)
Used reference for the scene, and for their outfits.
That's because in the movie his school has a certain uniform for fancy events like a ball. Their plain every-day uniform is brown, and this red one is the fancy one.