I didn't interpret anything as a smirk or see an eye roll, frustration maybe when you have Trump and Vance raising their voices at him and talking over him.

Talking out of both sides of your mouth typically means contradicting yourself or saying something opposite of what you've said in the past. Trump does that a LOT. Why Southern folks would say that means shrugs, smirks, etc... I have no idea. Must be a MAGA thing.