What indicates an emergency call from the Flight Deck to the FA on the Mid-Ceiling Exit sign?

An emergency call from the Flight Deck to the flight attendant is indicated by a flashing pink light on the Mid-Ceiling Exit sign. This specific signaling serves as a critical communication tool during emergencies, alerting flight attendants that urgent communication is necessary. The use of a unique color and flashing pattern ensures that the message is both noticeable and easily distinguishable from other indicators, allowing for quick recognition and response by the flight crew. This system is designed to maximize safety and facilitate effective communication in high-pressure situations.