Hal 9000 said:
I don’t have a problem with it at all. Force ghosts look bluish, glowy, and translucent. Han looks like how Ben remembers him. The scene plays out without some sort of distracting visual cue. I don’t know what one could even do that wouldn’t be inferred by some that he is a literal ghost.
I’m not saying Han should look like a ghost; I’m referring to the shots being edited so it could look like Kylo is having a hallucination rather than actually seeing Han in person.