From CBC News:
CNN made waves on Tuesday night by incorporating three-dimensional holograms into its coverage of the U.S. election. The only problem was, they weren’t really holograms.
“They were quite sophisticated, no doubt,” said Hans JÃ¼rgen Kreuzer, a professor of theoretical physics at Dalhousie University and an expert on holography who watched the 3-D interviews. “But I immediately said to my wife that I don’t think it has anything to do with holograms.” …
The CNN anchors were not really speaking to three-dimensional projected images, but rather empty space, Kreuzer said. The images were simply added to what viewers saw on their screens at home, in much the same way computer-generated special effects are added to movies.
Kreuzer said the images were tomograms, which are images that are captured from all sides, reconstructed by computers, then displayed on screen.