It's a concept that I've come to understand in couple's counseling. It's the idea of there being a defined, but accepted power differential in a relationship. A (typically) woman with the ability to have more power than what she currently has in her life, giving that power to her partner, will reciprocate by taking away responsibility and worry from the partner. Think of it as a sort of 'lease' on agency. If done healthily, a relationship like this has the man of the house making all of the important decisions in the home, commanding the household instead of cooperating within it, and, usually, being dominant force in intimacy. The tradeoff for the other partner is that the 'dominant' person will shoulder all responsibilities and concerns for the household. Bills, work, major life decisions, etc. In many ways the classical ideal. But Marston focused a bit more on the intimate side of the equation. Hence his penchant for sapphic scenes of Wonder Woman and her female companions in bondage. But the concept outside of the kink has been understood in marriage counseling for some time.