The component forms are much simpler (lines and circles only) than
for chess, so artistry is not the draw (yuk yuk), here.  Instead,
the Cool Hack IMHO is that the primary dimension (pixel length of a
square side) is computed based on window height, and moreover that
computation is user customizable (see ‘gnugo-d0-sizing-function’).

The end result is that the user can turn on the menu-bar (for
example) or resize the frame, and it's enough to type ‘i’ (to
toggle image-display mode) twice to have updated XPMs appear.
It's not real-time ("SIGWINCH" handler) resizing, but close enough
for me (and my slow computer :-D).

Also, it *almost* goes w/o mentioning: Generating XPM images on
the fly means less disk footprint, easier package management, no
search-path groveling, etc.  That's regardless of resize support.

-- 
Thien-Thi Nguyen
   GPG key: 4C807502
   (if you're human and you know it)
      read my lisp: (responsep (questions 'technical)
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                     => nil