"Natural Flavor
Why do I suspect this is completly unnatural and is only a title given to this thing,
whatever it actually is? After all, if this includes actual juice, why would it need a 
natural flavor as well? And what is it a flavor of?"
I worked as a co-op in a research lab for a chemical company in Georgia for 6 months.  While there, I worked with an ester compound that was used to produce over 150 different flavors.  Check the basic idea here:  www.chymist.com/esters.pdf
This compound was derived from pine tree stumps that the lumber/paper mill industry needed to get rid of.  Natural, see?