Oswald's outer shirt was hanging over his right shoulder when he was led through the building. It was hanging over his right shoulder, and that is all. So, what is the brown stuff at the bottom of the left side of Oswald's shirt?
I use the term "brown" although I know it's a black and white photo. It isn't black; it isn't white; so I'm calling it brown. But, I don't see how it got to the arrangement that we're seeing there. How is that shirt configured? How is it situated? And if his hands are cuffed behind his back, why can't we see it?