This is a very slow-motion gif of the Oswald shooting done by the Wizard, and it's very good because it shows very well what Oswald did. He first cringed forward and started going down, and then he veered back. Of course, there is no sign of any arm-slapping. That is seen in the Jackson photo and nowhere else .
The Shooter shot Oswald from the side, and of course, he had to since the bullet crossed Oswald's body from left to right. But, in the Jackson photo, the shooter is more in front of Oswald, with his back to the camera. The implication is that that was the position of the shooting, and it's commonly spoken of as if it was.
But, you only have to look at the gif to see that it was NOT the position of the shooting. And how it got to that in .3 second is very dubious and doubtful. We do not see the Jackson photo in the films, only in the Newsreel, when it appears as a still frame at the end of the film, to which they tacked it on.