I'm glad to see Juli finally offer Juliana the opportunity to switch places with her. I get the impression that Juliana doesn't get to experience the physical sensations that Juli does, when she is piloting her body. If Juli eats a tomato, Juliana doesn't get to taste it. She's basically just a ghost, experiencing only sight and sound, passively watching a stranger live her life for her, with her body. Then again, maybe I'm wrong on the physical sensations. We have seen some scenes in previous chapters where it looks like Juliana is holding a piece of fruit or tomato. Which would imply that she is tasting the food Juli eats for her. I wish they would spell this out.
It's beyond bizarre that Juliana wouldn't want to have a turn being back in her own body. There are a couple of reasons why she would be acting like this. A: She has a doormat type of personality, where she will place her own wants last, so that other people can be happy. B: She was depressed with her own life prior to Juli appearing, and has lost confidence in herself. So she just let's Juli live her life for her. C: Being a floating soul/ghost for an extended period of time, has had a negative effect on her. She has lost all ambition, desires, or goals. She just exists in a state of passive watching, unaware of how her personality has changed. D: Juliana is actually dead. She died and Juli reincarnated into her body. She may not be able to go back to her body anymore. And she is hiding this from Juli.