Danny’s reaction to Tommy’s joke shows that Danny is still adjusting to his family’s culture and sense of humor. Danny’s startled response may also suggest that he associates adults raising their voices with anger and violence. Based on Danny’s memory of his dad angrily attacking a stranger at the beach, it’s possible that Javier is angry and violent in other settings, too. Randy wearing a suit to Danny’s house and bringing champagne indicates that he has a lot of money.