If any people watching this are wondering who that girl is, her name is Marin Kitagawa from the anime "My Dress Up Darling" . This image of her is in the manga and hasn't been animated yet I believe.
I just caught up to the latest manga chapter, oh my god... I have no words other than I fucking LOVE MARIN OMG. Her cosplay (the one on this video) was SO GOOD. I recommend this manga a lottt!!!