You don't so much appreciate or interpret Sally Mann's photographs as you react to them. And the feelings, concepts, and emotions that Sally Mann evokes in her photographs are often uncomfortable ones. I believe this (apart from the whole 'naked children' hullabaloo, which is not entirely unrelated) is the reason many people are unnerved by her work. Yes, Sally Mann's work is undoubtedly disturbing. But it's also good. And the fact that it's so disturbing contributes to its level of 'goodness'.
Some people think art should only be beautiful, in a superficial sense. And while I'm partial to artistic explorations of the aesthetics of beauty, that's not the only thing art exists for. It exists to touch us in any number of ways - and not just positive, feel-good ways. Some people don't like 'dark' art. You might expect that I, as a horror fan and all that, am not unfriendly towards 'dark' art, and you would be right. I know that life is not all happiness, and I revel in the shadows. When I see the abyss reflected in art, I find myself relating to it, on some level. Artistic beauty is the heaven I strive towards - it's the fantasy I imagine in my head, the world I'd like to abide in. But the 'dark arts' are a reflection of the world that really exists, that I seem to be trapped in. And I find comfort in the fact that others recognize it as such, because there's nothing more irritating than somebody saying "don't worry, be happy" when so much sorrow surrounds you.
But the most fascinating aspect of Sally Mann's work is how much it reveals within the viewer: the interplay between the image - the real life moment in time it depicts - and the psychological concepts and emotions that we as viewers conjure up in the process of viewing it. Fans and critics alike testify that Sally Mann's photographs reveal uncomfortable truths, especially about childhood - truths that we are largely afraid to confront. But where we see images of death and violence and sexuality, I think a larger portion of that exists in the viewer's mind than it does in the moment depicted in the photograph. So that allegations about the ethics of Sally Mann's photography are largely misplaced. (There is also the argument about putting private moments out in public - but I am of the school of thought that believes that, provided those involved give their consent, there are no moments too intimate for exploration, even publicly, through art).
Take this image, "Jessie and the Deer":
I could probably do the same thing with any number of Sally Mann's images, but I think an examination of this image reveals what's going on in Mann's work. The first thing you notice about this image is how it makes you feel. And it probably makes you feel uncomfortable. A child's apparent happiness is contrasted with the stark reality of death. Mann's composition sells the image. Notice how the child's head, cocked to the side in a playful grin, mirrors the deer's head, hanging limply off the edge of the truck. This detail marries the two figures together, and the child becomes inextricably linked to the deer's corpse, and, by extension, death itself. Which forces us to acknowledge our own mortality, and - only slightly less morbid - the loss of our childhood innocence.
But most remarkable is the magic trick that Sally Mann has played on us. She has presented us with an image of a child and coated it in the symbolism of death. We fear for the child, and we reel at the tastelessness of the image. But strip it of all that symbolism and psychological weight and all we've got is a child living in the country, where activities like hunting (and wandering around naked) are probably just a mundane part of life for the child. She appears to be happy, after all. So why should we cry out against Sally for capturing these images, while thinking the child has somehow been abused or exploited in the process? It's not the individual child that has been put at risk (of death, and loss of innocence) - it is all of us, all the children in the world, and all the inner children hidden within us adults. It is the symbol of childhood, as well as life itself, that is being threatened in this image. And those are just concepts.
A very similar analysis could be made for The Alligator's Approach, or Hayhook, or The Terrible Picture, or any number of Sally's images. In fact, the entire concept is summed up nicely in the symbolism of the Candy Cigarette, one of Sally's more popular images. In it, we see a child apparently smoking a cigarette, and it scares us, but it's only candy. The abuse and neglect, the fear and death, the violence and sexuality, in these images - they are all candy cigarettes. In looking at them, we are reminded of the real terrors they represent, and we fear for the seemingly innocent children who are facing them. But those children are just living, like the rest of us. And even insofar as some of the terrors depicted might be real, or realistic, the subjects in the photos are in no more danger than we all are - and that, I think, is what truly scares us.
And I think it's rather short-sighted to say that Sally Mann shouldn't be taking images like these. These terrors won't go away if we don't think about them. But you do have the option of closing your eyes if you'd like not to be reminded. However, for the rest of us, who refuse to shut our eyes on the darker aspects of life, they serve as a study and a reminder - but not just that, as they are also beautiful images of [true] innocence standing up to overwhelming adversity, and great compositions from a purely artistic perspective to boot.