Consider this illustrative situation: A box of photographs appears to be safe in storage until the only person who can name the people in them is no longer available. The priority is to capture that context before choosing a book or film.
An elder's memory, a dispersed archive or an unwritten family history cannot be assumed to remain available later. The visible request may be a book, move, announcement, licence, archive, event or venture. The real question is what becomes harder to reverse once the first commitment is made.
Photographs and documents may survive while the people who can identify their meaning do not.