In Steven Universe we are introduced to a character named Lapis Lazuli. First we see her trapped in her mirror along with her gem being broken. Steven heals her and releases her from the mirror. As we learn about her we see that she was attacked by another gem during the rebellion, but what was she doing there?
We know that she was attacked despite being a non combatant (This is obviously a war crime). Lapis had an extensive knowledge about gem history and she has the ability to project images on flat, reflective surfaces like her mirror or still water.
What I am getting to here is, Lapis was on the battle field because she was supposed to record it. Lapis was a war reporter.