Does a duplicate stage copy data or run the entire job again?

As the title says, if I add a stage to my full backup does it simply copy that job out to another location or does it run the entire backup job again? 

I have two sites and some of the jobs I want to have the BE2012 data copied out to Site B from Site A. I have BE2012 at Site B but I don't want to run a second job from Site B across the link, I'd rather just copy the data instead of running a whole new job. 

This would lead into another question of whether or not I can simply copy the BE backup folder and use it later to restore?