N.Y. Multiple Dwelling Law § 51-b

§ 51-b. Mirrors in connection with self-service elevators. In all\nmultiple dwellings in which there are one or more self-service passenger\nelevators, there shall, pursuant to such regulations as the department\nshall prescribe, be affixed and maintained in each such elevator a\nmirror which will enable persons prior to entering into such elevator to\nview the inside thereof to determine whether any person is in such\nelevator.\n