[She holds her arm up, twisting it in front of her as though to appraise the idea and the imperfect disguise that comes with it, peering down at her body and then back to Diana.]

I'm you only smaller

Yes. And it must be complex, because it works in tandem with my imagination. Therefore, I am also limited by it. If you told me to change my appearance to match your friend, for example, I could only do so if that friend were mutual.