Fair enough. So the chain of trust is ... Personal credibility of the person taking the photo with iPhone (till the moment picture is taken) + tamper-evident

Fair enough. So the chain of trust is ... Personal credibility of the person taking the photo with iPhone (till the moment picture is taken) + tamper-evident protection against unauthorized or anonymous edits and manipulation (after the iphone photo is published and circulated) Apple cannot (of course) vouch for the former.