The Cambodia Daily article states the rules as new, but in reality they have been long-standing rules which state that commercial photography in Angkor must require a permit.
Government Imposes New Rules for Photos in Angkor Park
Cambodia Daily, 02 December 2015
Camera-wielding visitors to the iconic temples of the Angkor Archaeological Park in Siem Reap province will have to take extra care before clicking away now that the government has imposed new rules—effective immediately—for anyone aiming to make money off of their images.
As of December 1, all company representatives and journalists who want to take photographs inside the sprawling park, as well as tourists planning to profit from their photos or videos, must secure advance permission by filling out an application at the headquarters of the Apsara Authority, the government body that manages the World Heritage Site.
Full story here.