Detection layer: Photo
Only visible after taking a photo with the camera.
Photo anomalies are easy to miss because the patient can look normal before the camera is used. Take the photo, leave enough time to compare details, and do not admit the patient until the image matches the window view.
From Shift 4 onward, make photo comparison part of the normal check-in rhythm. A mismatch in ears, eyes, horns, face style, or image quality is enough to stop the admission.