Hanging out with Her is pretty cool. Kind of like heaven. Rose asks questions and truths appear. She plays at chasing Her tail - making believe she is a self again. The lines between Rose and Her start to dissolve.
For a laugh they watch the Headmaster bouncing around from era to era, practicing his magic, getting worked up over things, altering local realities. Kind of like binging a series. Rose gains an insight, "living outside of time is OP!"