In Caucasians, the upper lip stretches and thins as it ages. This is almost universal. One can see this clearly in older people — their upper teeth seem to disappear. Interestingly, the white border of the lower lip usually stays very close to the same place. But the red part of the lip (the vermilion) thins considerably. The sides of the lip drop a few milimeters. But more importantly, the corners of the mouth recede into the cheek, flattening the face and exaggerating the nasolabial crease. Because of overhang, the stretch of tissue and marionette lines, it appears that the corners of the mouth drop more than they actually do. It is the overhang of skin that gives the down-in-the-mouth look.
This patient is 32 in the younger picture, and 72 in the older image. Look at the thinning of both lips, and the stretch of the upper lip. The lower lip seems to roll in, but actually it thins.
This is another typical lip change with age. She is 19 in the younger image and 52 in the older. You will see these kinds of changes in almost all the images shown here.
This is a composite of two picture of Christopher Walken, one of my favorites. Most pictures from the internet are not similar enough to animate. The subjects are usually smiling. Finding a non-smiling pair this close is very rare. He is 25 in the younger image and 68 in the older. The overall face gives the impression of melting and descent.
Closer inspection reveals that the lower lid border doesn’t seem to have dropped. The nose stays stable, the cheeks thin. There is a large amount of shadow, which amplifies the cheek hollowing. The lips do what lips do: the upper lip stretches and the lower lip deflates. There really isn’t any drop of tissue until you get to the corner of the mouth, which is typical. Look at this for a while. You can’t trust first impressions.