When creating a Document Viewer post, you will see the configuration area under the shortcode area. From there you can configure the Document Viewer.

Sources
For the sources, upload a document file or you can select a file from Google Drive or Dropbox. To use Google Drive or Dropbox insert the keys in Settings.
Viewer
Select a Viewer.
- Google Doc Viewer (Word, Excel, Powerpoint, and PDF).
- Microsoft Online Viewer (Word, Excel, and Powerpoint).
- JS Viewer (PDF).
Options
Change the various options of the Document.
- Set the Width and Height.
- Show/hide the File Name on Top, Download Button on Top.
- Enable/disable Right Click.