You may remember this post about a configuration of parts on a framebuilder's drawing board. In the"Remarks" section, I invited guesses about what it was, and Justine was the one who got it: custom-made rear dropouts for a mixte frame.
Here they are in their transition from "caterpillar" to "butterfly".
Another mysterious shot of the frame in progress.
And another... Gee, I have a feeling that somebody who loves lugs would really appreciate a frame like this.
Hooray for the beautiful work of framebuilders - in this case the fabulous Royal H Cycles of Somerville, Massachusetts.