Colbay over at The Tango Hours mentioned it. Debbi at An Ever Fixed Mark touches on it in her private with Shorey.
You might call it follower energy. Or perhaps power. It's the concept of the follower not being passive at all. The absence of energy is what I have called a lazy follower. Not passive, active. Relaxed, but listening. Poised.
The leader leads with intention, the follower should follow with intention. Her intention to "take" the step. Not just take the step, but "TAKE" it. I'm having a hard time verbalizing what's in my mind on this. I will have to leave it at this - it's not just stepping. There's more to it.
Jaimes Freidgen has us do an exercise at a workshop once. In particular, it was on the molinete, and it was intended to illustrate the follower's energy level when taking her steps - back-side-forward - around the leader. He had the leaders stand on one foot, with the other leg extended out to the side, with a block frame. The follower was to take her steps around the leader, and pivot him on his active (standing) foot. First one way, then the leader changes feet and the follower goes the other way.
This energy level can be extended to walking and most/all other steps I would think. The crux is the delicate balance of it all. Not to seem lazy/flaccid, yet also not to seem too athletic, not to be backleading, or to feel like the follower is "getting away" from you or overstepping the lead.
I wonder, is this concept the difference between a heavy (feeling) and a light follower? Some followers (regardless of their physical stature) feel like a ton of bricks. Some feel like a feather mounted on ball bearings. These would be the two ends of the spectrum. I like it somewhere closer to the feather - but not too light.
This is a topic that I struggle with, when dancing with a few particular practice partners. Used to struggle with, since I no longer practice regularly. Eventually, I just gave up on it and kept my mouth shut.
Ladies? Your thoughts?