This is actually how pizza commercials get that stringy cheese-pull, they mix glue in with the cheese and nail down the slices next to the one to be pulled, usually hiding the nails under pepperoni or just more cheese. In addition to things like applying wax for sheen and post-processing effects. Nothing in food commercials is real.
Every time you see a pizza commercial now, just remember that prop they want you drooling over is no more edible than a child’s science fair project, and probably tastes twice as bad.