User blog comment:Kaido King of the Beasts/Chapter 832: Don't Judge this Rabbit/@comment-28966845-20160713134232/@comment-28966845-20160713134639

As for Brule i think she has a devil fruit givin her mirror powers. Bon could perfectly imitate a person's appearance and also he needed to touch that person first. When she transformed to Luffy his eye scar was on the wrong side, most likely a mirror ability. Also i dont think she ever got the chance to touch Luffy.