Reasons for Second Unmasking
Internet reasons:
She couldn't keep her hands off of his hideously disfigured gorgeous features.
She knew he'd try to escape the police, so she was saving his life.
To say, "Erik, let them see you as you are."
Thus when she rips off his mask, she unmasks his soul. She bears his heart out to not just herself, but the entire audience. Here is a mysterious man in all his power, glory, and beauty, diminished suddenly into an old, ugly, tragic child. She sets him free to the world: Erik, do not hide anymore. I see you as you really are. Neither good nor bad, he is now "just Erik!"
It was her point of no return and by ripping the mask off and unveiling his greatest weakness she proves that she is no longer his and never will be.
It's the PHANTOM'S opera, it was HIS opera house, and it was supposed to be HIS night of triumph. To have his mask removed during his own passionate work would render him powerless with humiliation and embarrassment.
A spontaneous thing because she wanted to see his face, have things be real between them.
She didn't see it clearly the first time and was curious.
There's a sizeable difference between two people undressing each other, and one person (ripping) the other's clothes off with no warning, when it's entirely unexpected. Sort of the equivalent of a "rape".
She shows him that she wants to be with him WITHOUT his mask...that she accepts and loves him as he really is.
She just wanted to know the man behind the mask.
The look of "Erik, I'm so sorry, but this can't be" she is pleading with her eyes for him to understand. His eyes are saying "WHY" and then "if I can't have you willingly, I will have you anyway I can get you".
To show him that with or without the mask she would never love him.
To show him that with or without the mask she would love him.
To prove to herself that his face means nothing.
She knew that if she did he would take her down to his lair and they could start their new life.
To show that even though it seems like he is the one controlling her, she is really in charge.
To show the audience that he's not as hideous as the rumors say and that he's really hot.
To finally get rid off all allusions: it's not the phantom of the opera, angel of music, or Don Juan, it's Erik. She wants to know him for who he really is.
To break herself out of his spell.
To protect herself from falling under his spell again.
Because it was actually written into the opera.
Her hand just happened to reach up to his face and accidentally knock it off.
She feels guilty about ever going along with the plan, so she tries to make the end less horrible for him.
To show everyone who he is so that the (world) is in on the story.
To say to the police "Look! It's the Phantom! Shoot him!"
Starting to undress him, as the whole song (point of no return) is about sex.
My brother's reason:
She's in a freakin' daze. She's all hypnotized. She didn't know what the heck she was doing.
My dad's reasons:
To show the people that he was a butt ugly freak.
Because it's just seemed the natural thing to do in the middle of a proposal.
To remind herself of how ugly he was so she wouldn't want him anymore.
My reasons:
It nicely interrupted his song.
They could have a big dramatic crescendo in the music.
The movie viewers could actually see his face.
To tick him off.
The chandelier could crash and everyone could DIE.
Kind of like saying "Ok, I'll stay, but you've got to take off the mask first and not be afraid of me."
Representing her decision in the most meaningful way to get through to him (although I think kissing him would've worked a lot better).
My friend's reason:
Definitely the idea that she was a sex-crazed maniac.