She once had a lot of respect and boasted the wealth of her household. But now she is being neglected in class and being treated exactly the opposite. In reality and on the stage, she's the vain girl, who wants to be a princess.
With the Black Tea Gentleman's power, today she is performing as a princess on a stage that exists only for her to see.
Incidently she does have a lot of acting ability. If she can put up with her current misfortunes, she'll surely blossom.