Cynthia decides to laze about on her towel, instead of re-wrapping it around her. Truthfully, this is Cynthia's personality. When she's at home, especially in her room, she has no real issues with being naked, even if others are around (and she especially loves it while Allea is around). Of course, Cynthia wouldn't just walk around in public or around her actual house naked... would she?

On a related note from the previous page, this is again part of why we were debating it. Having a scene where Cynthia is going to just sit around naked was like "We're going to have to find some creative way to cover this up, but still make it feel like she's just sitting around naturally, enjoying being naked".