I dunno, harmony sounds cooler than friendship and magic, and it’s technically a combination of both.

Princess Twilight Sparkle:

• as newly-ascended unicorn, Twilight still has a really long tail
  ** long, thin, and pointy horn means she’s very powerful magically and can cast complex spells
• small wings with large feathers, so she can glide easily, but it’s harder for her to fly since she lacks practice, experience, and wing volume. Twilight deals with this just by teleporting everywhere instead.
  ** small fan of pegasus tail feathers beginning to develop. She hasn’t gotten feather growth of her shoulders yet
• the only earth traits Twilight has picked up so far are small fetlocks behind her hooves.
  ** She has some earth pony blood, but her brother Shining Armor got more of it since he’s a lot more stockily built for a unicorn.

You know, when all the princess are put together, it looks like Celestia and Luna are watching Twilight do a magic trick while Cadence is arriving late to the party.

Wooo I’m done with all the princesses! I might to a few other random ones just for fun.