Because the picture was taken in 2010 when Biden was there in his official capacity as VP, he then asked to use a photo of him at Arlington in a ad and they allowed him to use that one 10 years after it was taken and not identifying anyone. Trump can do the same thing, and they would allow it as long as they control what the image shows to protect those buried there.
That is why the cemetery officials that were there tried to STOP Trump from filming and photographing in Section 60 since they would not have control of the images to protect the fallen buried there. Trump however is such a huge entitled asshat that he has his people physically remove her and threaten her to the point she was afraid to press charges. Now he is bashing those officials for doing their job to try and protect the fallen heros in Section 60 because they dare try to get in his way.....
OK let me tell you what the Army rules say. I know because I looked it up today. "Federal Law prohibits political campaign or election-related activities with in Army National military cemetaries to include photagraphers, content creators or any other persons in direct support of a partisan political canditate's campaign." So Woat did even if it was when he was VP, even if it he did get permision (Which I have seen no documentation on) he broke the law and used in an ad. End of story. Oh and once again, your side was invited 3 times to the same ceremony and blew it off.