I think it's about being in an abusive relationship. The woman used to be a pyramid, a hurricane, unstoppable, etc, but the relationship makes her a grain of sand, a gust of wind, etc. She's not the same person anymore, she's a shell. Basically it changed her from this strong, independent woman to a weak, vulnerable one.
My favorite part is when Katy sings about how she used to be a shell, but she turned herself back into a pearl. And the very last lyric "she is unstoppable", gives hope that the woman in this song left the abusive man and turned back into a pearl.
I think it's about being in an abusive relationship. The woman used to be a pyramid, a hurricane, unstoppable, etc, but the relationship makes her a grain of sand, a gust of wind, etc. She's not the same person anymore, she's a shell. Basically it changed her from this strong, independent woman to a weak, vulnerable one.
My favorite part is when Katy sings about how she used to be a shell, but she turned herself back into a pearl. And the very last lyric "she is unstoppable", gives hope that the woman in this song left the abusive man and turned back into a pearl.