I'm not sure, I would guess that Bob is simulating what it would look like for Alice to have desires, and I would not be surprised if the way human brains imple

I'm not sure, I would guess that Bob is simulating what it would look like for Alice to have desires, and I would not be surprised if the way human brains implemented "simulate what someone else's desires are" is the same way human brains implement "simulate the desires of the primary personality I act as". But I don't think it's the sort of question that gets resolved by thinking about it really hard, I think it's the sort of question that gets resolved by figuring out how to interpret what brains / piles of linear algebra are actually doing.