Facial recognition systems do not interpret human expressions the way people do. While humans can easily recognize a friend who is laughing or frowning, algorithms rely on fixed measurements and angles. A smile may widen the mouth, raise the cheeks, and narrow the eyes—all of which distort the standard facial geometry used in passport identification. This is why government agencies insist on a “neutral expression” for all official photos. The goal is to ensure that your passport image remains valid for the entire period of use, regardless of age or minor physical changes.
