Nothing is what it seems anymore
What is a hologram?
A hologram is a physical structure that diffracts light into an image. The term ‘hologram’ can refer to both the encoded material and the resulting image.
A holographic image can be seen by looking into an illuminated holographic print or by shining a laser through a hologram and projecting the image onto a screen.
Other methods of projecting and reflecting images are often described as holographic – or even misleadingly holograms, because they have an optical presence, spatial quality or iridescent colors.
http://holocenter.org/what-is-holography/
Aerial Burton 3D display projects images into mid-air
https://www.youtube.com/watch?v=GNoOiXkXmYQ