[2] According to author Clive Scott, this is another way of saying that a photograph has both a signified and a referent, is both coded and encoded.
Connotation (Semiotics) is arbitrary in that the meanings brought to the image are based on rules or conventions that the reader has learnt.
According to Roland Barthes the coded iconic message is the story that the image portrays.
An image of a bowl of fruit for example might imply still life, freshness or market stalls.
It is the "literal" denotation, the recognition of identifiable object in the photograph, irrespective of the larger societal code.