This is a great picture all around but I do have one question. Why is Luna wearing pants, I do feel like she is a better fighter than her sister in many ways but she's so pretty, she should be in an elegant dress. Luna is awesome either way. I really like the sword.
The Great Princess Luna, is the most excellent of excellent Swordswomans, she once defeated 10 Ursa Majors using nothing more than a practice fencing sword. This is why she is the most Excellent Great Princess Luna, Leader of the Luna Democratic Republic
I like how you've consistently dressed human-Luna in a Hussar-style military uniform, while Celestia (usually) remains in a traditional royal gown. I wonder if, as Luna matures, she takes a more "hands on" approach to some of Equestria's inconvenient problems.
Roving bands of diamond dog bandits, for example. <snicker> Celestia is a woman of words and intellect; so Luna becomes a woman of action.
It's a style of military dress uniform, largely from the 18th and 19th centuries, that was common in Europe. A lot of the time they had gilded chords on them (called Dolman style), but not always. The versions that Luna is wearing in these images seem like the less flashy "rag & bone" style, which don't have chords. But IMO they are more elegant, in a "less is more" kind of way.
If you look up "hussar jacket" on Google images, you'll get numerous images of both varieties. The style is popular among steampunk costume players.
That was probably more than you wanted to know, but I'm a historian by training; I couldn't help myself.
I can never understand why Hasbro has not taken advantage of this great character they created. She's perfect for the whole "Discovering Friendship" theme the show is all about. And yet we see nothing of her in Season 1, and just one episode of her in Season 2, she needs more screen time!