“Pomme” is slang for someone who is stupid, easily fooled. And ”mettre dans la vue” means “to take advantage on someone, to be ahead”.

From what you describe of the picture we have two adults: a man, his boss and the man’s child; the two men are playing and the kid’s watching them. But the caption would make more sense to me if the kid was playing with his dad’s boss.
Anyway here’s what I understand without more information: “Your boss is a real dunce, I’ve been ahead for five games/I’ve won five games.”