I think it depends on the person. Some people are auditory and would rather listen to an explanation. Others are visual and would rather see it. Some others may be kinesthetic and would rather feel it.
I think that we're all some combination of the above, although we may have different proportions. I tend to rather feel the technique but may sometimes need to see it from "the outside." Because of this, I'm usually one of the silent people on the mat (although I think some folks get intimidated by my overall silence)...