After his falling out with the family in the fifth book, Percy has walked out of a photo of the Weasley family. This suggests photographs can reflect what is happening with their subjects in real life.
A photograph of the Weasley family stood beside the in-tray. Harry noticed that Percy appeared to have walked out of it.
Order of the Phoenix - page 57 - Bloomsbury - chapter 8, The Hearing
However, in the seventh book when Harry finds a picture of the Marauders in Sirius' bedroom, all four boys are happy and laughing. One would think that the subjects of the photo would be angry/have walked out/etc in response to Wormtail's betrayal.
This was in contrast the only Wizarding photograph on the walls which was a picture of four Hogwarts students standing arm in arm, laughing at the camera.
Deathly Hallows - page 157 - Bloomsbury - chapter 10, Kreacher's Tale
What are the rules of the how subjects in magical photos act?
This is different from the question about photos and paintings because photos do not interact with real people like paintings do nor do they talk or make sounds. They seem to have a very different set of rules than paintings do. These rules seem to differ, however, depending on the portrait (which is what my question is about).