Tidhar's thesis supports the inclusion of the supernatural in my recent cataloging of steampunk pastiche elements, but expands our understanding of how these particular pastiche elements work together. If the pastiche elements I've identified continue to hold academic water over the course of my reading and observations, the nature of how the pastiche elements are in conversation with one another will have to be identified and investigated.
In addition to his own examples, I would add the way in which automata are often given "life" through kabbalistic means (see my post on Steamnocchio and the entry on the supernatural and automata in the pastiche post), which carries strong ties to other fusings of technology and the supernatural in steampunk: the god-like Victorian Wintermute of Sterling and Gibson's The Difference Engine, the disease that begins to turn men into machines in S.M. Peters' Whitechapel Gods, the miracle of creation made clockwork in Jay Lake's Mainspring (as well as the way in which Mainspring's messiah, Hethor Jacques can interact magically with the clockwork universe he inhabits), the alethiometer of Pullman's His Dark Materials (pictured at the top of the post), or the way Thomas Pynchon employs mathematics as a near ritual-magic means of changing aspects of time and space in Against the Day.
We might also merely construe the idea of technology becoming magical in a wide-eyed-wonder sort of way, in the sense that many steampunk technologies would require some form of magical impulsion or cohesion in order to be rendered plausible. Steampunk's merging of magic and technology permits the designs of DaVinci to not only be built, but to work, permits airship travel to be safe, and faster than we currently know to be possible. This relationship between magic and technology explains a great deal about the steampunk aesthetic, sometimes lampooned as being frivolous and pointless, merely wallowing about in the dregs of colonial adventure tales. It is also why I am hesitant to posit steampunk as pure SF, or fantasy, and why I resist the term "gaslamp fantasy" for it, since it gives too much attention to the word fantasy. Tidhar rightly points out that steampunk employs both magic and technology, not one or the other. Steampunk is pastiche, even at the level of genre - it is both fantasy and SF, in the way that space opera often is. This may not seem serious enough for the aficionado of hard SF, and in many cases, steampunk has no intention to be serious, to have a point, to make a political or social statement. There are examples of frivolous hard SF--or serious fiction which is merely well-structured word paintings, not thought experiments, nor cautionary or prescriptive tales. All genres have their fluff, even when the fluff is well written enough to be considered literature.
Likewise, when steampunk writers decide to say something, as in the case of Moorcock's Warlord of the Air, we realize that the magical technology of time travel is just another vehicle to move a character about in. The point of the story isn't so much about really travelling through time, but about being wide-eyed enough to entertain a new idea about what we've come to consider history, and to reflect upon the potential malleability of the history we are currently making.