Those supposed differences don't look all that different and something as simple as lighting and shadow differences between two photos can cause such things, not to mention all the photoshop type editing programs available today.
And the actual term that fits what people are trying to say here is "doppleganger" and not body double. Maybe that term sounds a little to far out, but people who are truly so identical in facial appearance don't exist outside of identical twins, and even they have some differences if one gets to know a set of twins well.
The word used in the article referenced was body double.
Doppleganger is probably a better term.