While Harriet is the FLPC in the timeline and thus is constantly away doing main character things, Batty is a cosmetic surgeon. It offers "complimentary exploratory surgery to beautify one's insides", which is just an excuse for it to take a peek inside and yoink anything that'd make an interesting specimen. It replaces the organs (most of the time)(most of the time with the same organ), so it can't understand what any fuss is about.

The client in this picture came in for a nosejob and got a free functional liver, how lucky!