The difference between my interpretation of fake and real writing, writing as performance and writing as communication, is linked to the difference between pretending and being. I have friends who argue that all being is performance. Now that I write this, I almost don't have the courage to go on with my thinking.
But I'm going to try. I'm going to bring this back to student writing. We know the difference between those essays (of whatever genre) that we love and do not like (hate) to read. I do not like to read essays (or people) that I interpret as performance--the writer being more focused on how rather than what she writes (some social class issues here). I love to read essays in which the writing didn't get in the way of what was being said.
It seems clear to me that when students are writing to demonstrate to the teacher their abilities to perform that there will be, except in accomplished performers, a constructed space between the writer and the written. In that space is dissonance. Maybe learning how to disguise dissonance as consonance is what we're after here, but I don't think so. I frankly shudder to thing that as educators we might be teaching our students how to perform rather than be. This might have something to do with why we don't like to read what they write. Maybe we're reading ourselves.