So apparently Mechagnome players cannot transmog their feet, wrist, and hand slots. Instead of transmogging these slots, you can choose between several arm and leg modification options to show off their metallic limbs.
Mechagnome players will have armor visible on the following slots: helm, shoulders, chest, cloak, waist, and legs. However, only the lower torso will show pants transmog; the actual legs are exposed metal.
Thoughts? Will it change your decision to roll a mechagnome?