There is a man looking at someone's picture and says:
Brothers and Sisters I have none,
but this man's father is my father's son.
Whose picture is the man looking at?
(In reply to
NOT Himself,selfish self,but his son,selfish son by Tim Axoy)
Lets use the same names expect let add one and this would be John's Father call him Joe.
Lets now take your second line "Jack's father is John's father's son.
Let's now just take John father's son.
Who is John's father? JOE! and who is joe's son? JOHN!
It is impossible for Joe to be a grandfather and a father to Jack! (barring sick stuff going on in the family).
The answer that the picture makes no sense no matter how you explain it because of that one line.
One more exercise here:
Lets change the word John's in that sentence to your (cause esentially he is talking about him)
Who is Your father's son? If you have no brother's or sisters it's you!