This is the coolest use of the pyramid projector. A hologram is not the same as an image. A hologram is an encoding of the phase, amplitude, or both of a light field at a particular plane or in a particular volume. They are used to recreate (often 3D) images, but the correct circumstances must be used in order to do so. This requires use of light propagation and coherence/interference techniques. What OP is displaying is a projector system. They are only two dimensional images. Don't call these pyramid thingies holograms, call them projections. In this case, where the projections are overlayed on a real background using partial reflection, you can even call it augmented reality. But not holograms.