Johnny can't help but misunderstand this remark as thinly veiled territorial jealousy, and it catches him off guard. Is he trying to make Johnny feel like he's less important to her? Maybe he's reading too much into it, but it makes him a little nervous, and he hesitates before changing the subject.

"You said you were a duplicate of the Doctor?" he says, tilting his head curiously. "How does that work?"