Concept:
This is a blood-relation puzzle that requires careful interpretation of family relationships, especially when indirect references are used.
Step-by-step explanation:
The man says, \emph{“I have no brother or sister.”}
Hence, his father’s son is himself.
He also says, \emph{“The father of the woman in the photograph is my father’s son.”}
Substituting from the first statement:
The father of the woman is the man himself.
Conclusion:
If the man himself is the father of the woman in the photograph, then the woman must be his daughter.
Final Answer: \(\boxed{\text{His daughter}}\)