I don't think that the two propositions "it is her" and "you are crazy" are mutually exclusive (as your 'or' implies they are). Even assuming it IS "her", the photo is very likely of a 15- or 16-year-old "her", that is to say, is from ten or eleven years ago. And what do we call someone who is still getting all aflutter, ten or eleven years on, about photos of a 15- or 16-year-old girl he never met? You guessed it: "crazy".
