According to current evidence, the photographer was approved to be onsite.
"Participants in the ceremony were made aware of federal laws, Army regulations and DoD policies, which clearly prohibit political activities on cemetery grounds," An ANC employee who attempted to ensure adherence to these rules was abruptly pushed aside. Consistent with the decorum expected at ANC, this employee acted with professionalism and avoided further disruption."
Trump is a scumbag. This might be a big reason why he loses in November.