The portrait

Puzzle Question:

A man was looking at a portrait. Someone asked him, "Whose picture are you looking at?"
He replied, pointing at the portrait: "Brothers and sisters have I none, but this man's son is my father's son."
Now whose picture is the man looking at?

Answer --

Solution of Puzzle:

The man is looking at his FATHER's portrait.
"my father's son" is the man himself as he do not have any brothers and sisters. So the statement reduces to "this man's son is myself." Now it is clear that the portrait is of his father.

Toughness:

Easy