No really, you don't want to see yourself right now. You look hideous.
What if every school in America took down all of their bathroom mirrors? Either girls would start to love themselves for what's on the inside or everyone would just be walking around with food in their teeth and cowlicks and their flies unzipped. The latter is clearly what the graffiti heckler thinks will happen, and she isn't happy about it. After all, the real world isn't like some blog full of confidence-boosting sentiments; it's like a blog full of bitches.