This page is an entry in the Key.
The term “trust chain” refers to all of the interlinked factors that affect how much viewers are likely to trust a photograph.
• the subject of the photograph
• the appearance of the photograph
• the reputation of the photographer
• the credibility of the context in which the photograph is encountered
• the presentation of the photograph (including the “Guaranteed TCQ” label and the photographer’s name)
• the presence or absence of any explanation or alerts regarding anything about the photo that looks “implausible, unrealistic, doctored, untrustworthy, or suspicious” (see here)
Most people trust photographs only as much as they trust the weakest component in the trust chain.
So for example if the viewer doesn’t trust “the context in which the photograph is encountered” (that’s #4 in the “disregard” list linked above), then — even if all of the other factors in the “trust chain” for the photograph are trustworthy — then the viewer is still likely to trust the photograph less.