Pointing to a photograph a man said, He is the father of only son of my sister. How is man related to photograph?              

Brother – in – law

Note:

↑ or ↓ ⇒ Upward or downward line shown "generation gap" .

   =    ⇒ Double lines shown "relation b/w Husband & Wife"

   —   ⇒ single line shown "relation among them other than Husband & Wife".

   +   ⇒ Plus sign shown " Male".

   -   ⇒minus sign shown " Female".