ImageMagick (display command) tries to print via an exec to the 'lp' command. Unless I failed to install the right printer rpm, my system has only 'lpr' so the result is that printing does not work from ImageMagick.
Thanks. That's fixed in our latest ImageMagick package, which will be in the next RawHide and the next Red Hat Linux. In the meantime, in /usr/X11R6/share/ImageMagick/delegates.mgk, change lp -c -s %i to lpr %i and it should work. You can even select your favorite printer there with lpr -P<something> %i if you like.