It is an option in MegaEdit to enable a watermarked preview from within the editor that a user can download and send to another user/manager etc before sending through to print. 

This setting can ONLY be enabled by an admin user - to activate go into the editor and click on Menu button :

Click Product Options:

Scroll down to find Additional Download Support:

There are a number of settings that can be altered:

PDF Download: = This enables the PDF Preview

Watermark Text: = This is the watermark text that will populate your preview

Restrict printing: = This setting enables whether the pdf preview can be print locked or not

Max page count: = This setting allows you to create a multipage PDF preview -1 = ALL pages 1/2/3 restricts the number of pages that will be previewed.

The below button will appear in the top right of the editor when the settings above are configured.