Bloody Mary (Nerve Endings)

I'm on board with those who think it's about a girl who grew up in an abusive home. The lines "See you laughing in a picture, but I know what's out of frame" refers to family pictures of her as a child, where she's seemingly happy, but the singer is saying he knows what happened when the camera wasn't there.

The next part ("You barely cried, but you made it out alive") means she stoically endured the abuse, but when she was finally able to get free, she did.

Then, "And I'm so proud that you're in my hands now," sounds kind of sinister at first, but it's really sincere, it's her husband saying that he really is proud of the fact that she survived her horrible childhood.

The chorus talks about the depression and self-loathing that she has to deal with as a victim. "Bloody Mary" is a game kids play where they lock themselves into a dark room, in front of a mirror, and "summon" the ghost of Bloody Mary. Typically the point is to freak themselves out, like telling ghost stories around a campfire. The keys to that reference are the fact that it's a totally self-inflicted horror - kids do this to themselves and sometimes get worked up into hysterics; and also that the effect of the game is similar to sensory deprivation, where your optic nerve starts playing tricks on you in the darkness, giving the illusion that you're seeing things that you can't possibly be seeing. So the chorus is really saying, "If we dwell on the horrors of the past it leads into self-inflicted depression." In effect, because she gets into these bouts of depression and dwells on her childhood, she's terrifying herself for no good reason, and more to the point, since "Bloody Mary" is just an illusion or trick, it's not real, and can't hurt her, just like her past can no longer hurt her, but she obsesses over the past anyway.

The other verses are expanding on the initial theme. "If we grew up together ... show you what you became" is saying he wishes he could go back into her childhood and tell her that no matter how horrible things are, her future is one of happiness. Then the next verse, "I'll never let them get closer, or shower you with any blame," is him saying he's there to protect her, and that her abusive family can't hurt her any more, while "Now we dance in our own picture where the rules have changed" refers to their wedding pictures (pictures of them dancing at their wedding), and that now that she's an adult and he's there to protect her, the rules have changed, and she's no longer subject to the rules and discipline that were used to terrorize her childhood.