It's very well done, although it looks a little sketchy and quick, but I have no idea as to whether you were going for that look or not, and I personally love it. It also needs a background, and you should have at least thrown Octavia's head poking in from the side of the frame, that may have been redundant though. All in all, it's impressive, amazing, and well done, and you should make more, specifically Octavia dressed like a straight thug. Keep up the good work!
Bluh, sorry it's taken a while to get to this; going to try and get through the folder today.
Anyhow! The sketchy style and lack of a background (even a simple color or gradient) give this a generally unfinished look. Also, I'm personally not a terribly huge fan of dialogue from off-screen when both parties are present in the scene. Especially so for something like this - I feel like you could get a lot of mileage out of a warmly smiling Octavia and a sheepish Vinyl interacting directly with each other (since both are things we don't get to see often).
That said, I quite like the costume - I kinda want to see it in more finished detail!
For a second there i tought the avatar was CoffeGrunts one. And iwas thinking, "mother if god, what i did this time?" Reading further i see not. Hm...more detail could be better indeed. Might make this gain some other time.