Example: Many records are only indexes, such as Social Security death indexes. An index, because it only a list, will only offer limited information, such as name and date and location of death.
For an image, the state where the death occurred will have had to allowed access to death certificates for scanning. In my research, Tennessee, North Carolina and Missouri have all been very generous with sharing death certificates. Michigan, on the hand, is very stingy with its documents, preferring instead to charge fees to access records.