The notion that there's a single "correct" interpretation of a film, as I talked about in my last post on the topic, is problematic. Sure, the movie has a story (so it's "about" the events), it has a directorial point of view (so it's "about" the director's intent), and both of these things are expressed using visual imagery and thematic language that's going to resonate with the target audience because of whatever makes that imagery and language emotionally effective (so it's "about" what makes the scary parts scary to a given audience). So, for example, The Shining is "about" a man who goes crazy while snowbound in an empty hotel. It's also "about" America's historical legacy of violence. Finally, it's "about" loneliness, isolation, the inability to provide for your family, and watching your marriage and family fall apart. Dissecting each of these is pretty much the basis of film scholarship.
I think horror movies get into trouble when one of these narratives is used to draw conclusions about another. I also think horror movies are especially vulnerable to this compared to other types of film. Specifically, there's what I think of as the "Any Movie Where…" effect, in which the events of the story and/or how they're portrayed are used to draw conclusions about directorial intent. Right now, I can't think of a better case example than The Human Centipede II: Full Sequence.
Director Tom Six was already skating on thin ice when he premiered The Human Centipede: First Sequence. The premise of the movie is that a crazy doctor attempts to graft three people together, connecting their digestive systems in the process, to create a conjoined triplet in the form of a centipede. No reason is given why he wants to do this, but that's okay, because do you really think you can reason with a dude like that? It's not a movie with character development, it's a movie with an inexorable thesis. Even within those constraints, it wasn't what most people seemed to expect - it was pretty restrained with its blood and gore, and a premium was placed on black humor and a bright, almost-sterile setting. It's a clean, cold movie, and given the basic ickiness of its premise, that works to its advantage.
The sequel is pretty much the aesthetic opposite of the first movie. It's shot in black and white (but still shot beautifully), and the entire movie takes place in spaces as raw and ugly as the first's were sleek and bright. Our protagonist this time is Martin. Martin is a round, bug-eyed, sweaty, oily little man. Martin doesn't talk on camera, he just grunts, whimpers, squeals, wheezes and hacks out asthmatic coughs between shots of his inhaler. His life is as small and cramped and ugly as the doctor's was urbane. He lives with his mother, who resents him for driving away her (sexually abusive) husband. He works the third shift at a parking garage, where he passes the time by watching his favorite movie over and over and over again, assembling a scrapbook from the movie, dreaming of the day when he can make the movie come true.
His favorite movie? Naturally, it's The Human Centipede.
Martin, as inept as the doctor was skilled, as hapless as the doctor was methodical, his tools as crude as the doctor's were surgical, wants to make his own human centipede. He is in no way equipped to do so, and he doesn't care. He gets his subjects by clocking them with a tire iron, he does the surgery with kitchen implements, attaches everyone with staples and duct tape. It is exactly as horrible as it sounds. The climax of the movie is an orgy of blood, shit, death, and humiliation, signifying little outside of itself. Which is not to say that it is a pointless movie. Like the first, it evokes a mood masterfully. Martin's world is cramped and squalid in all its features, soundtracked by industrial thumps and hisses, full of old brick, worn carpeting, dirty bedclothes, and shabby warehouse spaces. In many ways, it reminds me a lot of a less explicitly surreal Eraserhead. Both Martin and Henry have created something, and having done so, aren't sure what they should do with it. Martin chooses to play with his like a sadistic child, pulling the wings from flies on a horrifying scale.
Basically, the sequel is chock-full of fucking horrible things, ranging from the relevant to the completely gratuitous, and it's this gleeful wallowing in gore and filth and the casual abuse of the human body that has so many people contracting the vapors over it. And to be honest, I don't have nearly as easy a time defending this movie as I do The Human Centipede. If you've never seen the first movie, this one isn't going to make much sense to you. And you're going to be too busy crying, retching, and crying over how much retching you're doing to really take it in.
That said, as a companion to the first film, it works very well as another take on the same ideas - think of them as variations on a theme of Human Centipedes. Everything about the second is an aesthetic, narrative, and textual comment on the first. Martin's subhumanity and obsession with the first film signifies him as the stereotypical fan of the first film - who else would enjoy the first movie but a furtive, disgusting little deviant? Six can take jabs at both a section of horror film fandom and the critics who were so willing to dismiss the first film out of hand through Martin. The sordid violence of the second film pushes our worst expectations of the first in our faces, like saying "oh, you thought it was going to be a sick movie? This is a sick movie." It has the same undercurrent of black humor as the first film, but as relatively restrained (and no less chilling for it) as the first movie's denouement is, the second's is awful - not in quality, but in experience and implication. There's apparently a third movie planned, and I could see all three of them working together as sort of a triptych. The Human Centipede 2 is a very smart movie playing thuggish and dumb.
And that's where the relationship between intent and content gets tricky. Art uses extremes all the time - just look at the work of people like Chris Burden, Hermann Nitsch, Mark Pauline, and Matthew Barney for example. And sure, each one of these artists has had their detractors, but I think there's a lot less blanket dismissal based on specific content than in genre film.
If you, as a genre director, employ controversial, disturbing, graphic, or disgusting imagery, you run the risk of having your entire movie dismissed a priori merely based on the use of that imagery. "Any movie where you have (insert controversial thing here) is obviously just an attempt to shock people and attract controversy." Any attempt to talk about aesthetic or thematic choices is cut off before the conversation can even happen. "This is just pandering to gorehounds, because that's the only reason you'd ever show (insert controversial thing here) in a movie." It doesn't help when a subset of people respond to these movies with "I have to see this it sounds so fucked up and gross it'll be great LOL" when you're trying to make a serious argument for why a given movie should exist. If it's gross and it's in a genre film, it can't be art.
Of course, established and respected "serious" directors are largely exempt from this - Pier Pasolini featured child abuse and shit-eating in Salo, John Waters had weird chicken sex, singing anuses, forced impregnation and actual shit-eating in Pink Flamingos, Lars von Trier had hardcore sex and genital mutilation in Antichrist, and Harmony Korine had actual physical violence in Fight Harm (though that hasn't been released). And there are always people willing to apply the "Any Movie Where" heuristic to those movies, but there's at least enough leverage with each of these filmmakers to attempt a serious conversation. Try that with someone like Eli Roth, Tom Six, or Srdjan Spasojevic. Nope, when they do it, it's obviously just for cheap shocks. How could it possibly be anything else? It's just a horror film.
This is not to say that every horror film has artistic value. Good lord, some of them are complete shit. But at its best, horror is art, and sometimes that art goes very uncomfortable places, as art should be able to. It is possible to depict ugly, horrible things for something more substantial than cheap shocks. A movie is more than a collection of scenes, and genre is no reason to throw the consideration of context out the window. And honestly, I'd like to see more horror directors taken seriously earlier into their careers than usually happens. That's not going to happen until people stop assuming that the content of a film dictates the intent of the people who made it.