Previously: Who's the Saddest Girl? As the Saddest Girl is to singer-songwriters, so is the Different Girl to rockists and pop stars. Other girls are as alike as sands in the hourglass, but not she. She is like the bald eagle wearing a steel crown circling high above the prison fortress the hourglass is trapped in. It's hard to say what exactly makes her different, but rest assured that she is very much so. Whether…