No person, business, or owner, manager, operator or employee of any establishment shall sell, permit to be sold, offer for sale or display for sale any tobacco product, or point-of-sale tobacco promotional product, by means of self-service merchandising or by means other than vendor-assisted sales. Cartons of cigarettes, multi-packages of smokeless tobacco, cigars and pipe tobacco are exempt from this provision so long as these tobacco products are under constant direct sight surveillance of a store employee. These tobacco products shall be deemed to be under constant direct sight surveillance of an employee only if the tobacco products themselves (and not just the displays, racks, shelves, kiosks, etc., where the products are displayed) are in plain and full view of a store employee.