/usr/ports/graphics/ImageMagick looks suspiciously like the location in the FreeBSD ports collection that you would find ImageMagick and not the location it has been installed at all. You would cd to this directory and run make install to install ImageMagick. If ImageMagick was installed from ports on FreeBSD it would be in the same place as the other libraries and you wouldn't need to specify a different location using use lib

So I don't think they have installed it at all.

/J\