This is the formula for most of the intros Pharrell writes: looping the first beat of the first bar four times. Think of the beginnings to “Blurred Lines,” “Beautiful,” “Milkshake,” “Sweet Life,” etc. etc. etc. Better yet, listen to this collection.
The good news is that Pharrell isn’t lazy; and I’m certainly not one to knock pop’s tall-hatted leader. It’s his signature move, but it’s amazing no one noticed it until now.