The man in the picture is the onlooker’s son. Since he doesn’t have any brothers or sisters, the statement my father’s son can only be himself. A shortened version would be this man’s father is me, making him the father of the man in the picture.
I have seven letters and am something you eat. My only anagram can help your pain. If you remove my first 2 letters I wear things down. Removing my first 3 letters is an adjective and removing my first 4 letters leaves a measure of time.
Sausage. You eat sausage, assuage is the only single-word anagram and provides relief from pain. Usage wears things down, sage is an adjective and age is a measure of time.
There are six glasses in a row. The first three are full of water, and the next three are empty. By moving only one glass how can you make them alternate between full and empty?