Take it up with the town. Clearly stated. I bolded it for you but in case you cannot decipher what bolding illustrates, it illustrates medical mj grown on that site which is processed,(I will give you that one) or preserved, or packaged, or stored (hence the vault) falls under value added.

The following provisions shall apply to an agricultural use – value added, where it is permitted by this By-law:
a) the maximum gross floor area of the agricultural use – value added shall be 557.5 square metres;
b) the majority of the product processed, preserved, packaged and/or stored shall be from the farm;
c) the agricultural use – value added shall be operated by the owner of the farm;
d) the agricultural use – value added shall be secondary to the main agricultural use (i.e., the growing of crops) on the property;
e) employees shall be restricted to the owner and a maximum of five outside employees, full time or part time, on any given shift; and
f) the agricultural use – value added is subject to site plan control under Section 41 of the Planning Act.