We store most company files in box and have begun attaching them to the cards they relate to. Some users have the following options when they click attach, which is what the official trello documentation shows it should look like.

When I go to attach a file this is the dialog that opens up. 
We can add files from box using the power up but that requires us to go add it to existing boards when the functionality should exist out of the box. Any clue as to why I can't see the list of options?