So the common theory right now is that the original pink pearl was damaged by white diamond effectively turning her into a puppet ... what if it's the other way around? What if white pearl is the puppet master and white diamond the puppet?
We saw in Steven's dream that Pink Diamond and her pearl were close, they both had fun together, fooled yellow together etc., so what if pink pearl became the first "crystal gem" in a way, pink diamond seemed to treat her like an equal, juggling for her to make her happy when it's part of a Pearl's job to make her diamond happy (according to our pearl in Now we're only falling apart). Somehow it got into pearl's head that of she's equal to pink, of the diamonds are just gems like everyone else why shouldn't she rule?
Part of the reason I'm thinking this is because I asked myself why white would keep a damaged pearl around? If white had learned that pink tought her pearl to be independant she'd obviously put an end to that but why not just shatter her and be done with it? Keeping pink's pearl as a hollowed out "zombie" could have been a reminder for pink not to do it again but then why keep her after pink was supposedly shattered? Especially if white likes order and perfection so much ... why keep an outwardly damaged pearl?
So my theory is that at some point pink pearl managed to become white's pearl (no idea how she wormed her way into white's service but diamonds are not above being manipulated) and pink got a new one. After pink was gone and white heartbroken that could have been the moment for pearl to strike and she somehow incapacitated a weakened and distracted white damaging her own form in the process.
Pearl then changed her voice permanently to be able to speak as white diamond and she floats around holding the pose because that's how she keeps white diamond in place inside her ship.
At first glance white pearl looks like a victim of abuse but is she? Let's look at what actually happened when we saw her on homeworld, she showed up and that alone was enough to make the crowd go quiet, she then bossed yellow, blue and pink diamond around publically by telling pink to come and yellow and blue to stay put. Then she shows up at the ball and moves to the throne, she was literally on the throne so who's in charge on homeworld? Everyone including the other diamonds assumes white pearl is relaying white diamond's orders but she's also the only source for those orders.
Steven met white diamond but only for a short time and it wasn't an actual conversation, so it's possible white pearl controlled white diamond and kept it short because it is hard to not just keep her frozen inplace but to also have her speak.
This would also explain white diamonds apparent change in personality, in era one she seemed to be close tothe other diamonds, playing games with them, attending balls and avenging pink by blasting earth but then she completely detaches herself from everything for era two? That seems like an extreme change.
Some people think white diamond is literally seeing and speaking through her pearl but what's the point of remote controlling another body, why not just show up in person? If it was a way to observe her subjects anonymously that could be a reason but everyone is like "yikes, white's pearl" so there's nothing anonymous about it.
TL;DR: White Pearl is an evil mastermind and has taken control of homeworld.
