> With your suggested wording changes but without the pixelwise argument:
...
 >           (new-frame))

Please omit the parentheses here.
...
 >      (unless (display-graphic-p frame)

This is a fix you should mention in the commit message.
...

Please provide a diff to the current frame.el of master and a commit
message.  Have you done your Emacs paperwork already?  If not, I can
install this as a tiny change because it's short enough.  Still you
should start the paperwork since otherwise we cannot install further
changes from you.

Thanks, martin