The man's comment of being missed hits hard. Of course she's missed-- she's watched Serah spend three years of her life wishing she was home, and wanting to be home for her sister. But she couldn't because she was needed.

But she doesn't need this guy reminding her of her shortcomings, and locks all of that away. She can mull it over in private.

"It's all too elaborate to be a joke. We're all stuck here for the time being-- unless you somehow manage to get home." Like she had before, but she's back and... honestly she'd rather have been left alone.