I think I covered that with the paragraph after the one you quoted from: "The leader may surprise me with a completely unexpected move or use of a musical element I hadn't noticed, but it is a pleasant surprise that still makes total sense, even if it opens up the music to me in a new way. If I "hijack" the lead by using different timing than the leader expected, adding an embellishment, or even stepping differently than intended (deliberately), the leader doesn't think "WTF is she doing?". S/he thinks "I see what you did there! Cool!" and maybe even "Wait a sec! I can do THIS to follow what you did, and I never would have thought of it! We just invented a new thing!"