"…Now, you may remove your mask!"
After hearing Cyrus's gentle words, Hilda was very assured and finally remembered that the mask was still on her face. But unlike before, it no longer gives her that uncomfortable feeling.
Furthermore, she was going to reveal her face after over a decade of hiding it under that mask and in front of a man who she now has feeling nonetheless. So, she was somewhat shy and afraid at the same time.
Still, she knew she wasn't hideous and was told many times by her mother that she would be even more beautiful than her once she grew up, and her mother was the most beautiful woman she had ever seen.
So, calming her racing heart, she finally moved her hand to remove the mask on her face, and this time, without resistance, it left her face.