https://wccftech.com/resident-evil-village-guide-how-to-get-the-mask-of-pleasure/

In Resident Evil Village, you are looking for your daughter. Or at least Ethan Winters is. No one will blame you for forgetting a moment about her, given all the hand torture, vampires, and puzzles you’re meant to do on your way. But after checking exactly one cradle in Castle Dimitrescu, Ethan Winters is confident that Rose is elsewhere and your new objective is instead to escape. The only problem is you’ll need the four angel masks hidden around the castle to open the door.

Most of the masks are easy enough to find, thanks in part to the huge statue that holds them, but one is more difficult. The Mask of Pleasure is rigged so that removing it from the statue will seal you in the room, with seemingly the only way to escape being to reinstall the mask. This guide will break down exactly what you need to do to retrieve the Mask of Pleasure from Castle Dimitrescu and make your escape.