She's a princess and a saint, so she needs to keep up her act 24/7, more or less. However, she's not perfect either, because it's quite obvious she's not happy being the saint everyone admires. Just compare her extremely revealing dress to anyone else's in that dance hall. It's her not-so-subtle way of rebelling against her fate. Yet due to her years of standing in the spotlight, she can still keep acting as if she was perfectly content with her role, regardless of the contradictions.
There's actually some similarity between them: Leold, or rather Sendou Makoto, who was reborn into the body of a swine and has to live bearing that shame. And the princess born as a saint, who is expected to act accordingly, even though in reality she wants to be an erotic woman.