What is the purpose of the announcement? [originaltext]Flight 218 to Auckland In

Flight 218 to Auckland International Airport is now preparing for takeoff. "Please fasten your seatbelts. We’d like to remind everyone that laptop computers, tablets, and cellular phones should be turned off during takeoff and landing. Also, place any small carry-on bags underneath the seat in front of you and leave them there until the plane has taken off. You can access your belongings again once we are in the air. This aircraft is equipped with four emergency exit doors. Please identify the one nearest you. On behalf of all Rio Vista Airline employees, we’d like to thank you for flying with us today. We hope you have an enjoyable trip.