There is a chemical called oxcytocin that may be what you are talking about. My therapist makes voice recordings of particular ways to achieve relaxation or soothing. He thinks it is okay to use them just to hear his voice as well as for the purpose. Though he has never said anything about his picture, I think he would not see this as what a "total weirdo" would do, but rather a way to promote self-soothing and a reminder that someone is trustworthy.