Jupiter in Scorpio keeps their emotions to themselves: in a couple, their joy or sadness can’t always be read on their face. They may feel that showing them leaves them exposed.
Passion is a central ingredient. When an interest excites them, they find intensity and meaning in their life. If nothing awakens that energy, they may carry on as if on autopilot, doing what is necessary without feeling involved.
Power and authority interest them when they are part of what motivates them. Their willingness to exercise them depends less on the position itself than on the meaning it has within their interest of the moment.