What's That Bitch Talking About is a spoof game show featured on Saturday Night Live when Tina Fey hosted. The title can also double as a phrase used in conversation or in the classroom when an annoying person or teacher says something unbelievable and/or difficult to understand. It is said in code so the person being referred to as "bitch" is unaware and therefore not offended.
Bob: Dude, what's that BTA?
Rob: I have no clue man.
Girlfriend: Joe you said you'd call me in the morning when you woke up!
Joe to friend: What's that BTA now?