I didn't see it, but I just watched it on YouTube. From the way she described it, though, it's not what I would call a hologram. Wolf Blitzer couldn't actually
see her. They were basically just superimposing video of her on top of video of Blitzer's studio in real-time.
It's more complicated but essentially the same technology that lets them put the little glowing flare on the puck in hockey games or showing the first-down line across the field in football games. You don't see it if you're there "live," only if you're watching the broadcast.
EDIT: But I'm dissapointed Yellin didn't take the opportunity to say, "Help me, Obi-Wan Kenobi. You're my only hope."
