NEW YORK — We've heard plenty about Facebook COO Sheryl Sandberg's management style without ever seeing it firsthand. Until today. Before joining an Advertising Week panel on stage at the Paley Center for Media, Sandberg rounded up a coterie of Facebookers in the lobby and gave them something of a motivational speech. I was there with my handy Flip camera to capture the two-minute speech. Unfortunately, the lobby was loud and unless any of you are lipreaders (email us if you are), we won't know what Sandberg said. Still, I think there's plenty of body language to examine as Facebook's real boss holds court with her minions and their heavy bags. Does their silence speak of admiring attention, resentment or fear?