Generally in football, a quarterback can fake a play by mimicking a handoff to a running back or fullback and instead keeping the ball, in an attempt to deceive the defense and to allow extra time for a passing play. That's how it's traditionally done, anyway.
Who was he faking to? Certainly not the back; the back was on the other side of him. It's this kind of diabolical, groundbreaking thinking that makes Leinart so dangerous. What is he going to do next? Literally no one knows.
Congratulations, Matt Leinart, you modern-day football genius. I think somebody just earned a starting quarterback job.