The description of what users are looking at is inconsistent in our language describing the interface.
On the page for creating a newsletter the opening starts with "This page allows you to create a new newsletter". On the page for unsubscribing it states, "This interface allows you to unsubscribe from "Tech Showcase" newsletter." Emphasis added.
We should pick one way of describing what users are looking at. Is it a "page" or is it an "interface". I suggest the former, "page", as it's more common of a word and sounds less technical than "interface".