Edit the uploaded image by changing only the visible facial expression of the person to a natural, realistic sad expression. Preserve the person’s identity, facial structure, skin texture, hairstyle, pose, body position, clothing, accessories, background, lighting, camera angle, framing, and image style. Do not change the overall composition or any non-expression details. Make the sadness subtle and believable rather than exaggerated: slightly raise and draw together the inner eyebrows, soften the eyes, add a faintly downcast or emotionally heavy gaze, and gently turn the corners of the mouth downward. Keep the lips and cheeks natural. If appropriate, add a very slight sense of eye moisture, but do not add dramatic tears unless they already fit the scene naturally. Maintain photorealism and seamless facial coherence. Ensure the edited expression blends naturally with the original head pose, lighting, and facial proportions. Avoid over-editing, avoid changing age or attractiveness, and avoid introducing artifacts, distortion, asymmetry, or unintended emotion changes. Priority: expression change only; everything else should remain unchanged.
