What must a flight attendant do when a passenger moves to an exit seat after takeoff?

When a passenger moves to an exit seat after takeoff, it is crucial for the flight attendant to ensure that the passenger meets the criteria necessary for sitting in that specific seat. Exit seats are designated for individuals who are able and willing to assist in an emergency evacuation. Therefore, having the passenger review the exit seat criteria and confirm their ability to assist not only ensures the safety of everyone on board but also complies with airline regulations regarding exit row seating.

This process involves explaining the responsibilities associated with sitting in an exit row, which may include the physical capability to open the exit door and help other passengers in an evacuation scenario. By confirming the passenger's understanding and willingness to undertake these responsibilities, the flight attendant ensures that all safety protocols are adhered to, enhancing the overall safety of the flight.