I saw this youtube video at the “Art of Experience” blog and was immediately intrigued. Truthfully I am not sure if I can register the difference in facial expression by this speaker but I like his teaching. It resonates with my reading of the “Social Engagement System” by Stephen Porges, MD and how this develops social attachment and bonding between mother and child. The SES is what triggers our fight, flight or freeze reactions to overwhelming stressors. The speaker in this video is coming from a salesmanship orientation and not a clinical psychology/researcher point of view but he is dead on (no pun intended) about how your facial expression can enhance your personal relationship, be they business or social.
It reminds me of the research on “still face” experiments where a parent stops being animated with an infant and just goes “still” or expressionless. The baby will try to get the parent to interact, cry when that doesn’t work and then emotionally shuts down. This has a lot of implications for depressed parents or parents who are drug addicts leaving little to no face-to-face interaction with the child. This results in a child who cannot bond with adults or develops a disordered attachment style.
Often in my therapeutic work with children I will be extra animated with attachment disordered children to help them be aware of social communication/signals and read them accurately. Engagement is a key element in their treatment. They need the extra effort to feel it is safe to trust our facial expressions and start learning from them.
Try the OPEN Face for a few days and tell me if you see any difference in your life. It will make me smile 
