The Office announcement blog HERE does a great job of illustrating what the integration does and how it works.
However, our customers brought up some very valid concerns regarding the integration. So we wanted to quell some of the misconceptions and tell you what it can’t do, as it’s easy to make assumptions about how it all works.
Read more at source: http://blogs.technet.com/b/office_web_apps_server_2013_support_blog/archive/2015/05/08/clarifications-on-dropbox-integration-with-office-online.aspx
