The Song is about a young beautiful woman (Tiffany) coming to grounds with her personality flaws(Im a Piece of Art). She understands that she is not moving towards being a better person but is at a moral stand still. While her friends seek to help her by assuring her that she is just fine,( My friends all Lie and say) She sees her friends as shallow, and not understanding self betterment. The chorus depicts
(Tiffany) in her vanity (3,2,1 it goes like). She is extremely beautiful on the outside but lacks depth and the ability to change. Her beauty is rare but only serves as a front ( like a little Black Dress that will soon fade). Patrick Stump reveals that as she ages her inner ugly will fade her beauty.And leave her destitute and empty (But you'll be faded soon, stuck on a little hot mess)