Seeing that my self is your other, and your self is my other, Zhuangzi asks if there is really any self or other at all. If not, then there is a kind oneness that emerges from the merging of the one into the other. "It is only someone who really gets through them that can see how the two sides open into each other to form a oneness." (2:23; Ziporyn) It is easy enough to understand this in theory, but to really "get through them" is another thing altogether; it must be a transformative experience like that of Ziqi who consequentially loses his "me". Since self/other leads to "this/that", the fundamental distinction of thought, to transcend it is already to go where words cannot go; the transcendence of self/other cannot be imagined. (Though trying to imagine it might be a way of approximating it.)
To experience this — or at least to begin to approximate it however imperfectly — leads to a unique psychological paradigm shift which, though Zhuangzi seems much more interested in one's inner experience, also works itself out in behavioral changes in the world. "It is just a matter of going along with the present 'this'. To do this without knowing it, and not because you have defined it as right, is called 'the Course' [Dao]". (2:23) It is having an open, untethered mind.
This is the heart of the reasoned side of Zhuangzi's project of showing a way to freedom from the "separating pen" of one's own narrow subjectivity. Ziporyn calls it the "wild card mind" and, I think I can safely say, sees it as the defining concept of Zhuangzi's way. His elucidation of having such a mind is quite elaborate, and I won't attempt to reproduce it here, but will sketch the broad parameters.
Imagine you are playing a card game (the basics of which is to pick up and discard cards) in which you do not know the rules (as in life) though you keep picking up cards that provide you with contradictory rules. One card tells you to keep high cards; another says keep low cards, etc. For the wild card mind this poses no problem, for it has no commitment to any one kind of card or set of rules, but is by its nature able to transform along with whatever the current situation requires. Now an ace, now a deuce; "now a horse, now an ox".
The wild card mind is thus typified by infinite flexibility by virtue of being unfixed from any one point of view. It is like taking a walk in the woods, appreciating the full gamut of sounds and sights as all equally expressions of the Great Happening. Or, as I like to say, it is the ability to appreciate humanity and its expressions as we might the competing interests of various species of ants, appreciating them all, committing to none.
You can check out Scott's writings on Zhuangzi here.