Documents missing from the "Create Posts" drop-down within groups

After enabling the Commons Documents feature, on group's main page there is no option on the green "Create Posts" drop-down for adding a new document. Instead, my options for adding documents to a group are to either A) click on the Documents tab/button on a group's main page and then click on "Create a document" button or B) click on the Add Content shortcut and then the "Documents" link.

Technically, I don't see a link in the drop-down on the mockup, but it's not clear to me why it wouldn't be. I suspect this is an issue, but please correct me if it's working as designed.