…make me laugh! 
Apparently, they do it to establish the “connection” with the anchor, and due to satellite time-lag they hear their lead-in some few seconds after we hear it here in the States, but it still is very comical to watch them bobbing their heads to absolutely nothing they are hearing!
Surely there must be a better way to ensure a seamless reportage? Maybe a key-word, or an atomic-clock set time?
I’ll bob my head up and down while you Dopers formulate an answer!
Q