Aman while looking at a photograph said, "brothers and sisters have i none. that man's father is my father's son." who was the person in the photograph?
explain your answer.

If the man's father is his son, then the man is his grandson. :)

The man speaking is the person in the photograph.
He said he had no brother or sister, and for that you be his father's son in the photograph, it would have to be he himself in the photo.
Hope this helps.