How a person presents themselves, or what they choose to show to the world.
If a person's face appears differently in a dream than in reality, consider how it is different—it may be saying something about how you view that person. For example, your mother's face appearing 30 years younger than she is could mean that you think of her as young-at-heart.
Random faces often show up during twilight sleep, when you are dropping off to sleep or waking up. These can seem like they carry significant meaning when they actually do not.