Why does Jack Donaghy look up when he drinks?

I am a big fan of 30 Rock. Great writing, acting, etc.

Alec Baldwin is awesome as Jack Donaghy. There’s one thing that he does for the character that sticks out, and I don’t entirely understand it.

When someone is smiling, it means they’re happy. If there are tears running down their face and their mouth is turned downward, it means they’re sad. These are obvious facial cues.

Every time Donaghy takes a drink on the show, he looks up at the ceiling.

This is the best image I could find, but he does it every single time in the show. I don’t understand what it means. Why is that consistently a part of the character. Does Alec Baldwin naturally look up at the ceiling when he drinks?

Last time I put a question on the internet like this (“Why is there a lobster carved into the Notre Dame Cathedral?“) with a $20 bounty on the answer, I got an answer fast.

Internet — it’s your turn again. $20 for a credible answer to this question. Either something referencing an acting class, face-eye psychology info, or a more official source.