Strange or unnatural-looking human faces often show up in AI picture editing for a few key reasons:
1.
Human faces are highly sensitive to distortions
- We’re evolutionarily tuned to recognize faces with incredible precision. Even tiny misalignments in the eyes, mouth, or symmetry can look “off” to us.
- AI models that generate or edit images might not preserve these subtle relationships perfectly, so we quickly notice when something’s wrong.
2.
Accumulation of artifacts with multiple edits
- Each edit the AI makes introduces small changes. One modification might be fine, but as edits stack up, the model has to “guess” repeatedly, which can cause blurry details, mismatched lighting, or warping.
- This is especially true if edits are applied to compressed images (like JPEGs), where the AI already has less information to work with.
3.
Overfitting to patterns rather than true anatomy
- Image models are trained on huge datasets, but they don’t understand why a face looks the way it does — they just learn statistical patterns.
- When pushed with multiple modifications, they sometimes “hallucinate” features (extra teeth, asymmetrical eyes, distorted ears) because they’re recombining patterns in unnatural ways.
4.
Resolution and context mismatches
- Many AI tools work at fixed resolutions. When editing, the model may need to “upscale” or “blend” details, which can lead to mismatched sharpness between the face and surrounding areas.
- If context (like lighting, pose, or background) isn’t consistent, the AI may generate a face that looks pasted-on or uncanny.
5.
The “uncanny valley” effect
- Even when faces are close to correct, small errors (slightly glassy eyes, stiff smiles, skin textures that look plastic-like) make them fall into the uncanny valley. They look almost human — but not quite — which feels unsettling.
In short: faces are uniquely difficult for AI to edit realistically because they require extreme precision, and repeated modifications tend to amplify small errors into obvious distortions.