Haven't been here in awhile, but just read everything from the top down to this article so far.

Just wanted to add that I once saw (or read?) something about how "ad wizards" (to use a Seinfeld term) photograph fast food. When it comes to burgers, they often make a slice from the center of the patty to the back edge. The slice can then be spread apart (so it looks more like PacMan with his mouth open) so the patty looks wider when the finished product is photographed from the front.

Notice how all the ad pictures show these burgers head-on, rather than from any other angle that would allow you to see that cut around the back side. The patties can also be positioned so they hang off the front edge of the bun, adding to the illusion, since again -- you can't see how they wind up NOT hanging off the back side of the bun.

In most cases, photographers will also use meat that wasn't quite cooked ALL the way like the burgers you get at the store. Those black grill lines are added specifically by a hot metal probe. That also explains why the meat you see in the ads usually has "squarer corners" than the flimsy-looking patties we're served in the real world.

And let's not forget about Photoshop. They can airbrush a photo of a burger just as easily as they can airbrush the blemishes off a celebrity's magazine cover shots.