The manual says that the SMILE SHOT Scene works in the shooting standby mode. How is the shooting standby mode enabled?
When the SMILE SHOT Scene is selected, it automatically puts the camera into the shooting standby mode. When the camera is in the shooting standby mode, it is waiting to detect a smiling face in the frame. When the camera detects a smiling face, it automatically shoots three shots in rapid succession without the shutter button being pressed. If the shutter button is pressed while SMILE SHOT is enabled, the camera will shoot a burst of three frames whether or not a smiling face is detected. When SMILE SHOT is enabled, the Self-Timer/AF Illuminator lamp is lit.
When the SMILE SHOT scene is selected, it automatically puts the camera into the shooting standby mode. When the camera is in the shooting standby mode, it is waiting to detect a smiling face in the frame. When the camera detects a smiling face, it automatically shoots a picture without the shutter button being pressed. If the shutter button is pressed while SMILE SHOT is enabled, the camera will shoot a picture whether or not a smiling face is detected. When SMILE SHOT is enabled, the Self-Timer/AF Illuminator lamp is lit.