So, that is a right thumb clasping a left hand on the right, and it's similar to what we see on the left. And below that, you can see the two shirt cuffs. And, the one wrist ends right where it goes straight across. How could it possibly be shaped the way it is?
That is a monstrosity. No human hand is like that. Oswald's arm-slap was faked. He didn't do it. This is definitely bogus, and it doesn't occur in any other imagery.