Replace the **billboard advertisement shown in the original subway video** with the **uploaded photo**.
Use the uploaded photo as the **only billboard image reference**. Keep the uploaded image recognizable and preserve its original subject, facial features, colors, and composition as much as possible.
Keep **everything else in the original video exactly the same**, including:
* subway station environment
* train/platform movement
* people and objects in the scene
* billboard size and physical structure
* camera angle and framing
* camera movement
* perspective changes
* lighting and shadows
* reflections
* video speed and duration
* original reveal timing
* all background details and visual effects
The uploaded photo must appear **naturally printed or displayed on the billboard surface**, not floating in front of it.
As the camera moves through the subway scene, accurately track the billboard so the uploaded image follows the billboard’s:
* perspective
* angle
* scale
* position
* motion blur
* partial occlusions
* reflections and environmental lighting
If the billboard enters the frame gradually, preserve the exact same reveal. If it becomes more frontal or larger during the camera movement, dynamically adjust the uploaded image so it remains perfectly attached to the billboard surface.
Maintain realistic billboard texture and brightness. The uploaded photo should inherit the original display’s light level, contrast, slight glare, and any screen or printed-surface characteristics.
Do not alter or regenerate the rest of the subway scene.
Avoid:
* changing the billboard location or dimensions
* replacing other signs or screens
* stretching or warping the uploaded photo unnaturally
* floating image edges
* perspective mismatch
* flickering between the original ad and uploaded image
* changing the camera movement
* changing the station, train, people, or surroundings