Why the viewers of Citizen Kane are an essential part of the film

Rating: 10/10 (20 January 2009)

Famously in the film Citizen Kane the title character Charles Foster Kane dies in his bed, muttering "Rosebud" and dropping a snow globe, without anybody other than Kane being visible in the room. Yet the whole film is based on the premise that "Rosebud" was Kane's last word and a reporter tries to find out the meaning of the word by interviewing people who knew him. So how could he do this if nobody heard him say the word? Towards the end of the film the butler claims that he was in the room when Kane died. We never saw him in the bedroom but not the whole room was shown to us, so it is very much possible. But why is it that he wasn't shown to us being in the room when Kane died? Given how extremely well thought through the film is it is more than likely that this wasn't only done intentionally, but with a purpose.
The film mostly is told to us (quite literally) from a subjective point of view and through opinions of people who knew Charles Foster Kane. And Kane was a different kind of person depending on who told the story. A main message of the film - so to speak - is that there is no actual picture of a person, there are just many different fragmented pictures of which none are true or false.
In the very first scene of the film we see a sign that says "No Trespassing". This sort of makes us the intruders to Xanadu and to Kane's life. The camera goes through his garden around the castle leading into the castle. So in the beginning we, like, become another one of those subjective witnesses who try to get the "full picture" and who eventually will form an opinion about this person. And to include the viewer into this bunch of unreliable witnesses and to manifest the concept that we are in the same position as all of those characters who told us THEIR story of Kane's life, the viewer obviously (for now) is the only witness to the first act of 'Citizen Kane' and the last chapter of Kane's life. It is this very event that gets the stone rolling. It makes us a witness and now the investigation of Kane's past life can begin.
Now if you think of the interviewer/reporter who asks the people for Kane's story, we mostly see him from behind with the camera looking over his shoulders. Or he is obscured by shadows, a hat and (observating) glasses. Often he simply is off-screen altogether and we apparently are the interviewees' only listeners. The poor man is pretty much faceless. One could say that the interviewer, who never is fleshed out as a character - if you can even call him a character with an own identity - is taking the position of the viewer who witnessed his last word and who wants to find out what it means.
You could look at it as an inside joke by Welles, that the very premise of the film is based on what initially looks like a goof. He waits until the last interview to tell us that the butler was actually in the room to witness the word, and now the film doesn't need us as witnesses anymore. We are done being witnesses, as now we have created our own individual image of Charles Foster Kane in our mind, based on everything we saw and heard. Maybe soon another viewer will trespass the the barriers of Xanadu, wondering who this man was. And this time he will walk up to us and ask us who Charles Foster Kane was, and we will be glad to tell him.