Mirrors tend to be everyones first thought yes, but there are hundreds of different ways we could use a copy of player skin for NPCs or Dialog.
Also, a special mirror default would be nice, but I have no idea how it would be possible to only record the body data and not the uniform data for one to work. I can think of plenty of excuses for them wearing the same uniform as the player. I'm content eating this elephant one bite at a time.
I'd be happy to start out with just the captain's total duplicate; there are plenty of possibilities for use in that. To duplicate the body and reverse the uniform would require for body and clothing to be separated in the Foundry's costume creator, and that's a ways off at best.