There are so many things that one can't hope to ever understand. This Darth Vader Hologram Bobble-head would be one such object.
I'm sure that George Lucas and some of his marketing buddies were sitting around trying to think up something extra special for this year's Comic Con when they realized that Darth Vader not only sent many messages via hologram, but he had a head large enough to be turned into a bobble-head without much resizing. That's really the best explanation that I've got.
In all honesty it looks more like Darth Vader died and came back as a blue glowie similar to Yoda and Obi-wan, which is not the case. I imagine that once removed from its packaging (if you dare) any Star Wars geek friends of yours will be quite confused. You won't have to worry about confusing them too much though, less than 1500 of these will actually be produced.
Darth Vader Hologram Bobblehead [via uberreview]