Creating a discussion and reply in the discussion are added by the author of the Page only from the page name. Adding Announcements happens in a similar way.
You can add the option to add these elements as a user or as a Page name(Screenshot - 56.jpg Screenshot - 57.jpg Screenshot - 58.jpg).
If the ad is added to page's Followers, then the name displays the name of the Page(Screenshot - 59.jpg).
Attachments can only be downloaded by logged in users