Ancient Discoveries

[Venkman]

On History Channel. It's not a new show, but I'm curious about this bit of tech they've used on it recently:

You've got this guy doing some explanation behind a table. He's got a glove thing on with a bunch balls hanging off of it on straight spikes (for 3D mocap position I assume). Above his hand though is floating what looks like a hologram in perfect sync with his hand.

His eyes seem to be tracking perfectly with it, but he could just be doing the weatherman thing of looking at a monitor off screen. It's a bit unnervingly like sci-fi holograms though, so I was curious if anyone knew the tech behind it (assuming it's not mundane smoke and mirrors).