Oh sure, if not unfinished then perhaps “just for a sizzle reel”. Like they got Henry in quick, already had the set all built anyway, and captured the footage right there just for that purpose, never intended to be part of the movie.
Of course if you want to over-think it there was once a version of the movie without CGI Tarkin at all, where ILM decided not to go there, and he’s only ever seen from behind like that. But they decided to go down the stupid path.