IDENTITY PRESERVATION INSTRUCTION: Using the uploaded photo as reference, preserve the person's exact facial features, face shape, eye color, skin tone, and unique characteristics while transforming the expression to show the reaction of tasting unsweetened coffee for the first time.

TRANSFORMATION DESCRIPTION: Apply a natural, subtle facial expression of surprise and contemplation as if trying strong black coffee without sugar. The expression should show: slight squinting of eyes from the unexpected bitterness, lips pressed together in a tight line or slightly puckered, a subtle furrow in the brow showing thoughtful processing of the taste, and a hint of surprise in the eyes. The expression must be authentic and relatable, not exaggerated or cartoonish. Maintain the person's natural facial structure and expressions while adding this specific reaction.

STYLE AND AESTHETIC PARAMETERS:
- Photorealistic style matching the quality and lighting of the original photo
- Natural, candid portrait photography aesthetic
- Soft to medium lighting that flatters facial features and captures subtle expressions
- Warm or neutral color palette depending on original photo
- Background should remain consistent or be subtly blurred to keep focus on facial expression
- High detail on facial micro-expressions and skin texture
- Cinematic depth of field with focus on the face
- Professional headshot quality with emotional authenticity

TECHNICAL QUALITY PARAMETERS:
- High resolution, 4K, detailed
- Sharp focus on face and particularly on eyes and mouth to capture expression
- Professional quality portrait
- Natural skin texture preserved
- Clean edges and seamless transformation
- Aspect ratio: match original or use 4:5 for portrait

NEGATIVE PROMPT GUIDANCE: Avoid: distorted features, unrealistic proportions, blurry face, loss of likeness, exaggerated cartoonish expressions, unnatural facial contortions, mismatched lighting, artificial-looking skin, inconsistent eye alignment

USER CUSTOMIZATION: {additional_context}

ADDITIONAL TIPS:
- For best results, use a clear front-facing photo with good lighting
- If the original photo already has an expression, this prompt will transform it naturally
- Adjust the {additional_context} to specify if you want more/less dramatic reaction
- Works best with portraits showing at least shoulders and face clearly