Identify visible information
Describe the people, objects, and actions actually shown. A book visible in a frame does not by itself establish every detail of the event around it.
Read the photograph's design
Notice camera distance, crop, and gesture. These choices can emphasise a personal exchange, a crowd, or the book as an object.
Keep provenance separate
A reliable caption or first-hand note can supply context. Use it accurately and distinguish it from an inference made only from the image.