This isn't comparing X11 emacs to vi, it's emacs (built w/ a no-x11 switch) on NetBSD compared w/ native nvi. If this were an X11 enabled binary, you'd see links to various X11 libs and GUI toolkits, similar to this xterm:

        /usr/X11R7/bin/xterm:
                -lXft.3 => /usr/X11R7/lib/libXft.so.3
                -lX11.7 => /usr/X11R7/lib/libX11.so.7
                -lxcb.2 => /usr/X11R7/lib/libxcb.so.2
                -lXau.7 => /usr/X11R7/lib/libXau.so.7
                -lc.12 => /usr/lib/libc.so.12
                -lXdmcp.7 => /usr/X11R7/lib/libXdmcp.so.7
                -lfontconfig.2 => /usr/X11R7/lib/libfontconfig.so.2
                -lexpat.2 => /usr/lib/libexpat.so.2
                -lfreetype.18 => /usr/X11R7/lib/libfreetype.so.18
                -lz.1 => /usr/lib/libz.so.1
                -lbz2.1 => /usr/lib/libbz2.so.1
                -lXrandr.3 => /usr/X11R7/lib/libXrandr.so.3
                -lXrender.2 => /usr/X11R7/lib/libXrender.so.2
                -lXext.7 => /usr/X11R7/lib/libXext.so.7
                -lXaw7.10 => /usr/X11R7/lib/libXaw7.so.10
                -lXmu.7 => /usr/X11R7/lib/libXmu.so.7
                -lXt.7 => /usr/X11R7/lib/libXt.so.7
                -lSM.7 => /usr/X11R7/lib/libSM.so.7
                -lICE.7 => /usr/X11R7/lib/libICE.so.7
                -lXpm.5 => /usr/X11R7/lib/libXpm.so.5
                -lXinerama.2 => /usr/X11R7/lib/libXinerama.so.2
                -lcurses.7 => /usr/lib/libcurses.so.7
                -lterminfo.1 => /usr/lib/libterminfo.so.1
                -lutil.7 => /usr/lib/libutil.so.7