1) A play on words, encapsulating charismatic flair in a flirtatious and sultry nature via metaphorical innuendo -- backing you up and drawing you in... all at once.
2) The act of someone impressing, astounding, or entertaining another -- more of an art than a skill...
3) A phrase coined by Jami, queen face-rocker.
"Bringing me an iced tea would totally rock my face right now..."
"Join my army of face-rocking minions and start rocking faces today!" -- Jami, irockyourface.com
"Now that I have the new iPhone, I rock your face!"