The following videos describe relational mindfulness in simple terms (total: 11 minutes).
This 4-minute video uses the analogy of wounded fists rubbing each other to describe what happens when people trigger each other.
This 2-minute video addresses defensiveness:
This 5-minute video puts relational mindfulness within the context of neuroscience:
This is related to the notion of Sunflower Mind.
See also: Sunflower Mind: The embodied & relational edge of Focusing-oriented therapy.