Notice the yellow areas of the front teeth, especially near the gumline. Notice how thin the teeth appear, even grey-looking in the outline of the front teeth. Notice that the biting edges have all flattened.
After
Now, see how white, but still natural the teeth look. Notice that this porcelain work has many characteristics that make them look like normal teeth, not carbon-copy veneers. Notice that the biting edges are longer, re-creating youthfulness!