He sees the kid. He gets offered the milk, but refuses it because he’s a vegan and vegans don’t drink cow’s milk or any other animal’s milk. If he was able to drink the milk he would’ve seen the “missing” picture of the kid and remembered that he had just seen him walk by earlier. He could’ve told someone about seeing the kid and they could’ve gotten him away from whoever it was that had him and took him back to his family.