Moving from Principal to Head is metaphorical to what I imagine it must be like moving from Congressman to Senator. It’s a bit more prestigious, due in some part to the fact that the club is smaller and the responsibilities grow. And there is, within that club, a huge difference between the clout which a senator from a state rich in population and wealth wields (akin to Heads from schools such as Sidwell, Maret, Georgetown Prep, etc.), and, say, the senator from North Dakota (Thornton Friends). Because while it’s a nice job, and you get a cushy chair, outside of those who live and breathe within the political boundaries of North Dakota, no one really gives a darn.
And that is good, for it is as it should be.