Still Young Indy

After two super short shots of a plane about to take off and Mikkelsen’s character now in a more formal Nazi uniform, we get this odd shot of Indy. It looks like it’s still young Indy, only how would this scene, possibly on a train, fit in with the Nazi flashback? Are there multiple flashbacks? Why is he shocked? Is Indy… seeing himself? To me, this frame out of all of them, is the one that just really doesn’t fit. Curious.