Facial symmetry: a mirror comparison, thrown off by a tilted head.

A facial symmetry test takes landmark positions — eye corners, brow height, jaw edge, mouth corners — splits the face down the midline, and compares each point against its mirrored counterpart on the other side. Small differences are normal; every real face has some. The score is just a summary of how much left and right diverge in that one frame, not a judgment about which side is "correct."

A mirror comparison only means something if the face was actually square to the camera. Turn your head a few degrees off-axis (yaw) or tilt it slightly (roll), and one side of the face moves closer to the lens while the other moves away — which changes apparent landmark spacing on each side independently, even though your face didn't change at all. Off-center lighting adds a second distortion: a shadow falling across one cheek reads to a landmark model as structure, not illumination. Of the six ratios Mogalytics tracks, frame symmetry is one of the more pose-sensitive — see the full breakdown of why scores swing between scans for the other camera variables that move a reading the same way. A single uploaded photo can't correct for any of this after the fact.

The fix isn't a better single photo, it's ruling out head angle and lighting as the variable before trusting the number. Face the lens straight-on, keep light even on both sides of the face, and take more than one reading — the practice guide covers framing and lighting in more detail. If your symmetry reading still moves once pose and light are controlled for, that's a more meaningful signal than any single photo can give you.

Mogalytics tracks frame symmetry as one of six weighted geometry ratios — alongside eye line, jaw ratio, midface, cheek ratio, and bridge — settled over a 30-frame trimmed-mean window so a single head turn doesn't define the result. It's read live from your own camera on-device, not from one uploaded photo, so you can check your pose against the lens, adjust, and check again in the same session instead of guessing from a single shot. See what the full composite tier actually means once you have a stable reading, and how to track it across sessions rather than trusting any one scan.

Frame symmetry is one piece of a six-measurement composite. If you're auditing the rest: canthal tilt is distorted by the same head-angle problem from a different axis; midface ratio is thrown off by camera distance instead of pose; and the nose bridge ratio is skewed by angle for a structural reason specific to the bridge's shape.