Favor Zoom Scale
The output map image will be at the same zoom scale as is displayed on screen,
but the top or sides may be clipped in order to fit the shape of the Page Template.
Favor Map Extent
The output map image will contain all the current features visible on screen,
but may zoom out further to fit the shape of the Page Template.
Note, I'm currently having problems with my 'secure' layers and they won't export correctly. I'll remove this message when I get it working again...