well, since the environment around her changes, and the color of her hair and dress change, that rules out pepper's ghost. around the three minute mark, when there's bursts around her or whatever, that if you pause it, it's confined to a square. that shows the resolution. she never moves, so if it's a projection hologram (like the one in star wars episode four) then the projectors would have to be nearby (which would explain why it's so dark) if you look at her feet, there's a ring around it. so my bet is that it's a projection hologram. as i said before, the projectors would have to be small, and there would be ones shooting from different angles, merged together to created the 3-D, or hologram, effect.

at the end, though, when she disengrates, it looks as if it's two-dimensional... maybe that's just the camera that's shooting it...

if you have any other questions, feel free to email me