In this case you’d still need a way to know who the photographer is and whether they can be trusted. The photographer at the beginning of the chain can sign anything, regardless of if it’s a real photograph or edited (or a real photograph of a staged scene with fake location/time data). The cryptography system could only tell you that the image originates with the same person or organisation who is associated with a specific cryptographic key.
It’s a reference to Aella’s statistical analysis of how many people came to her birthday