In the section where Will Smith's character is on the scene in Central Park(?) to inspect the area where Lara Flynn Boyle's character's ship has landed, Smith communicated back to HQ (Rip Torn - Agent Zed) through a device that has a camera (proven by the fact that when the shot changed to the HQ, Agent Zed can see Smith on a monitor). Notice how after a few exchanges with Agent Zed, Smith turns off (or at least he wasn't facing)this communication device. Still, you will notice that when the shot changes back to Agent Zed in HQ, he still talks to Smith in the monitor as if Smith was still looking/communicating through the device (which he already turned off/wasn't directly looking at).