Pressing this button opens a save file dialog, where you can specify the filename for exported sub-set and chose a folder.
This feature is essentialy the same as the above, but the newly created file is attached to an Outlook mail (if you have Outlook installed).
This button is just calling the native MS Office 'Create pdf/xps', which is an often overlooked feature.
Pressing the button opens a save file dialog, then on the dialog:
To learn more about this feature see Microsoft's documentation: