Exactly as the title says, if you want to show off your art skills or just give a rough image of your sword put it here!
I encourage drawing all the forms of your sword (Sealed to Bankai/Resurrección and the sheathes)*
*But i would like to remind everyone that just because you know what you want it to look like doesn't mean you can get it, as the zanpakuto template says the rank for bankai is captain and especially strong lieutenants and the rank for shikai is yet to be determined but will likely also be within the higher seated positions to prevent server lag from all the abilities.