Alternate commentary teams

Something I've always wondered about in the modern era's world of separate RAW and Smackdown commentary teams at the PPVs. When one team is calling the match on TV, the other team is still sitting there. They seem engaged… not looking around the arena or casually chatting, etc. What are they doing? Are they calling the match as well? Preparing for their next match? Playing with their phones? 

I'd assume they're Twittering or getting instructions from Vince on the headset.  Never really thought about it.