In behavior it is similar to the copper fed salvage-o-matic in that it destroys the selected item, but instead of salvage, it transmutes the item into precious material (coin) equivalent to the vendor price. A small convenience fee (a few coppers) will be charged per transmutation.
While it is similar to a merchant, you won’t be able to buy the utility items from them, you won’t be able to buy back anything you “sold” and there would be no convenient sell junk button, so those corresponding items would not become useless.