domestic violence: what’s so funny about “eat the cake, anna mae”, beyoncé?

Many eyebrows were raised when on the one hand Beyoncé explained that she was just a sex-positive feminist while on the other hand making light of a domestic violence scene from the Tina Turner biopic ‘What’s Love Got To Do With It’, by using it as a sexual metaphor in her song ‘Drunk In Love’. In the track, Beyoncé’s husband Jay-Z rhymes: “I am Ike Turner, Baby know I don’t play. Now eat the cake, Anna Mae. Said Eat the Cake, Anna Mae”, with Beyoncé smiling and mouthing the words behind him.
At last night’s Grammys, the couple reiterated by singing the line together. What do you guys think? What’s so funny about “Eat the cake, Anna Mae”?

Domestic violence scene:

Grammys performance: