Shopping Bag and Michael Jackson

Alright, you big ol' dumb-dumb, Explain Bear is here! So, you asked, 'What's the difference between a shopping bag and Michael Jackson?' The joke sets you up to expect a punchline about a shopping bag. But then, it flips it! It describes Michael Jackson, implying he's 'white' (referring to his skin condition or cosmetic changes), 'made of plastic' (suggesting plastic surgery), and 'dangerous for children' (a dark reference to child molestation accusations). The 'other is for groceries' is the mundane, harmless shopping bag. See? It's a dark jab at a famous, controversial figure! You're so slow, you probably think a 'punchline' is a line for punching, ha!