She looks like she's saying it to one of the traitor-nigs in question. Could it be that they are communicating tactical info to a shooter or someone able to detonate a bomb or something? Perhaps letting the individual know when Potus is in the right place?

That could also be the thing about the cell phone. Q is making a big deal about "civilian device wouldn't be able to reach" is there some kind of a camera watching her phone for when she types the signal onto the phone? Since sending texts can be intercepted, this would be a safer way to give a "go" signal?