I cooked myself a hamburger today, which though of good quality, the strings of meat which form it were very visible. Whenever I see such strings of meat there are two images which immediately come into consciousness. The first is some German painter's version of the hand machine used to create it. I can't remember the painter or precisely the painting, as it's a vague memory, but the machine is something like this one: . 
The second, and the much stronger memory, is a beautiful film by Jean Eustach called The Pig (le cochon). Surprisingly this movie does not seem to exist on DVD.
The movie is a 50 minute documentary of a slaughtering of a big pig in a small farmhouse in the French countryside. Starting from the slaughtering to then the use of each and every part of the pig. Nothing goes to waste. They use the blood, the skin, every minuscule part of the pig is used for something. It is quite incredible to watch, and has definitely stayed with me ever since.
What's nice about the movie is that it really shows you the usefulness of the pig, even through the sometimes horrifying images. This is contrary to a film like The blood of beasts (Les sang des bêtes) of Georges Franju which humanizes animals in showing us the awful cruelty of man towards animals. (Also, a must see film). As I mentioned elsewhere, I'm not a vegeterian , but this movie certainly makes you feel bad about the road they took to your plate.

The point of this is to note how certain images never leave us. It is not clear why certain ones remain and certain ones pass quickly. There are of course traumatic images, but mostly certain images simply ingrained themselves on us, which is what images want to do. The history of painting starts with the image of christ ingrained on a towel given to him (The legend of st. Veronica's shroud), and this is what images do to us, sometimes. But why certain ones? Do they have to have shocked us?