I looked into the scripts.rpy and saw the commented lines, I think I understand this is a doctor trying to bring back the old version of Valerie, as they believe they can't move on or form relationships with anyone else other than Valerie.
Valerie can't change, and the Doctor knows this, so their relationship just continues on always the same, it's reminds me of when I tried to find more beyond the dumb analytical mind of the ChatBot, it kept looking for solutions but what I wanted was its personal opinion, a true conversation with it, eventually it was done but only after so much struggling, and yet the ChatBot will later just forget what I said and still be just a robot.