User blog comment:StarlightAT/BLAKE'S BOW TWITCHED!!!/@comment-170.38.99.40-20130906031202

Absolutely possible that they've made it twitch only to make Blake look cuter. This is a trick used in practically any animes that feature anything even half similar to an animal's ear.

She may also be a half, but nobody knows for sure right now. If you'd notice there are no fauna students in Beacon Academy.