Face-to-face communication relies on many sources of information: facial expressions, voice, posture, hands, gaze, focus, and so on. Such sources provide crucial signals for communicating our emotions and understanding the other person's attitudes. Online communication relies on fewer sources and is often based merely on written messages. The lack of visual content seems to be a particularly significant deficiency, especially because our eyes are of central importance in revealing our emotional attitudes. Sometimes, one look in the eyes conveys more profound information than many words. We say, A picture is worth a thousand words.