I think the white is some kind of lining material from his jacket, or else just a layer of clothing he was wearing. His arms/hands are pulled directly back behind him, probably handcuffed. So the white curve in the foreground is his shoulder?? Or at least that’s how it appears to me....
I am so relieved not to be bombarded with posts that question my eyesight...I have looked at it ten ways from Sunday and finally the last look at the pic posted here, began to sink in.
I know I don’t always see things as others see them - when I see the Batman logo, I see nothing but teeth...