The link is on every page, in the strip under the header. Copy sends it to the clipboard. It does not enrol a machine by itself.
The address on the strip is what you send. A machine installed from it is tagged site/Melbourne and stays enrolled in Example Co. It is not a second company. Copy puts that address on the clipboard. Opening it shows the install page. You cannot rotate the link, and you cannot turn it off.
The computers that link would join are See the computers you were given. Your provider turns the link on in Give a customer their own install link, picks the group in Choose the group a customer's new machines join, and replaces the URL in Rotate a customer's install link.