When tsuwm or Faldage return, we'll get down to what the rhetorical turn is called.

Until then, how about inverted metaphor [or "inverted aphorism"]?

"The Inverted Metaphor:

In the inverted metaphor, the primary and secondary subjects are switched in the sentence frame to create an "adjective-noun" construction. Here's an example:

foxy John

and you may snicker because you realize that, in English as in the idioms of other languages as well, "word order" affects "word meaning"--that "John, the fox" doesn't carry quite the same message as "foxy John"!"