The picture above, and the video below the divide are examples of relatively mundane technology at work. It's actually quite simple. The image was projected by standard equipment you might see in an office or a nice college lecture room, onto a standing piece of glass that had been treated with Vikuiti Projection Film and cut into the shape of the lady's silhouette. With the video set to loop, visitors to the area could be treated to a piece of nice bright signage.
Do you see the incredible otaku potential in such things? What if we could cut that glass in properly moe shape, perhaps ones to match the members of a certain high school's music club, then play their concerts in three-dimensional 2D! It'd just be like that scene from Minority Report where Tom Cruise can't stop playing hologram videos of his wife. There would be no creepy uncanny valley incidents like with RealDolls or faculty members, just the super-amazing equivalent of a wallscroll or standee! Kind of a video figurine for you Tomopop-types.
Now, if you'll excuse me, I'm off to go find some panes of glass.
I don't think it would work for live concerts since the characters would be stuck to a single pose and would not be able to move. However, the technology is nice.
It's even more creepy because they don't move at all. A concert with a few of those would be more uncanny than an animatronic show. Also they reflect light.