I get your point, but I think a representation of a hologram is a representation of a hologram, regardless of whether or not the subject is a fictional character.
Plus, I can't think of many good alternatives to calling representations of holograms anything but "holograms".
You could call it a "virtual protest", but "virtual" is a weak and vague term. It's really more suggestive of VR or AR technology.
"virtual projection" is better than "virtual" on its own, and would work in this case. But it doesn't work for the many well-known hologram effects that are done using Pepper's ghost (like 2pac, MJ, etc), because those are reflections, not projections. It replaces one technically inaccurate term with another.
"pseudo-hologram" is the best blanket term I can think of.
Eventually though, in 50 to 100 years, we will have actual video hologram tech. People will then be able to see and understand the difference, and these cheap smoke and mirror tricks will be abandoned, and the problem will go away on its own. :-)