Al Hirschfeld was a man who liked to draw cartoons. He was really good at drawing pictures of people, especially famous ones like actors and musicians.
But what made his drawings special was that he would hide the name "Nina" somewhere in each picture. Nina was the name of his daughter, and he did this as a way to honor her.
People would try to find the Nina in each picture, and it became sort of like a game. Some people even collected his drawings because they were so cool and unique.
Al Hirschfeld passed away when he was very old, but his drawings are still famous and people still try to find the hidden Ninas in them.