Either photoshopped or from the wear and tear on both shoes, were given to them before they started their journey. But, the shoes are not so worn that would prove they didn’t walk across all those thousands of miles acros the desert.
On the other point, yes, they show wear, but not what would be expected from a 1,000 mile trek. Maybe they're some kind of get-out-of-jail-free cards telling the cops and cartels, "Don't ef with me, I've got protection."