I suspect, though Dai can correct me if I am wrong, that his book is fundamentally different to Swift's Mirror of the Free, in that, again I suspect from some of the above, Dai takes a far more eclectic approach, and allows various sources to inform the precision of the imagery used.
Perhaps a quote from Coomaraswamy (something I used a number of years ago on AT in relation to tarot) may here be mentioned again. He writes (Nature of Buddhist Art)
Symbolism is a language and a precise form of thought; it is a hieratic and a metaphysical language and not a language determined by somatic or psychological categories. Its foundation is in analogical correspondences [...] symbolism is a calculus in the same sense that an adequate analogy is a proof.