1. Kyoko's socks in the school uniform are a bit shorter. Probably just below the knees from what I remember. 2. Past Homura's socks are just below the knees. New Homura's socks are like the socks in the picture. 3. Mami's shoes are white and a different design.
As a little side note, Kyoko never actually went to school in the anime, but I supplies you could draw her with the uniform anyways. Also Miami's stockings were white, but whatever. This drawing is awesome and really nicely detailed. Their positions really tell a lot about the characters. Good job!
Gorgeous picture, really captures the emotion of the anime very well! Only slight issues is that Mami's shoes are white in the anime and Kyoko was never seen wearing the uniform-although on that note, I suppose it could be argued as a 'what if' scenario, which would make a lot more sense. As I said, they're just very small issues, the beauty of this piece does outshine any negativity Great job!