Setting up a good retention and deletion policy for digital photographs and graphics is highly important. This policy needs to take in to account how to deal with variations and versioning of these assets. Determining for your business what is the best version to keep.
Keeping a photograph or graphic for the short or long term will also determine what format these assets should be kept in. A graphic might not need to be kept if it has little reuse value and is archived as part of a document. On the whole an original photograph with RAW file and metadata would be better kept than a variation that has been highly edited. For long term archival storage it is important to consider using digital formats that will be easily accessible on hardware and software in the future. Choosing a non-archival format for graphics and photographs may mean that they are inaccessible to your organization in 2, 5 or 10 years when technology has moved on.