I'm honestly not sure whether what you're talking (thinking) about is or isn't the same as what I'm talking about
What I'm talking about is basically the same exact thing as you (well, me anyhow) would do in a roundpen with a mostly-stationary horse (i.e., minus the "make the horse trot or canter round and round" parts of roundpenning), where the leadrope is slack and does not actually DO anything at all, it is just to keep the horse from getting bored and wandering off <g>.
You get the horse to lower its head, step one step this way or that way or the other way, follow you around, turn, yield, start, stop, etc etc. Most of it is done at the halt, or moving just a couple steps at a time.
There is a really really good book by Bill Dorrance that's the best description of this sort of thing I know of, but plenty of other more-trendy-popular-spendy NH advocates do at least *some* of this type stuff too.
Mind, I say this as more of a classical dressage and h/j person, NOT any type of NH aficionado
The thing is, it is awfully awfully useful to you and the horse, and can be done anytime anywhere with any horse whatsoever, even when it's on layup for some reason, and pays all *sorts* of dividends when done properly and with emphasis on finesse and 'natural correctness' of the horse's movement.
(btw, sorry, NOT trying to hijack Lupinfarm's journal

, and of course there *are* plenty of things a roundpen is somewhat useful for so it is always nice to have if you happen to have the spare change

)
JME,
Pat