Oswald in the doorway: the blog of the Oswald Innocence Campaign, by Ralph Cinque

Here we see Babushka Lady taking a picture, and JFK and Jackie seem to be in the same arrangement as in the Moorman photo.

Now remember, everything only happened once. Here is Mary Moorman at the time.

I don't think Mary Moorman had her camera up at that time. Let's hone in.

It's hard to tell what Mary Moorman is doing on the left, but there is no way the motorcycle cop would be captured in her photo at this time as it is in the Moorman photo. 

Obviously, whoever took that picture was shooting from behind the motorcycle cop, meaning that motorcycle cop had already passed her. So obviously, this could not have been when Mary took her picture, as the motorcycle cop hadn't passed her yet. 

 So, we have the Moorman photo, and although we don't have a Babushka Lady photo, we do have a photo taken by someone else. 

I don't say those images were taken at the exact same time, but I am saying that they had to be very close in time, meaning within a small fraction of a second of each other. But, how could Mary Moorman have taken the image on the left? She couldn't have taken it a fraction of a second earlier because the motorcycle cop would have been that much farther away and impossible to capture.

Could Mary have taken it a fraction of a second after this picture?

We know what happens after this. Kennedy's head keeps going back and to the left. Jackie goes forward to get out of the way. Then she comes back to him briefly, and then she begins her trek to the back of the car. The arrangement that we see here does not occur again. It was a fleeting thing. 

So, what it means is that Mary Moorman could not have been taking her picture at the same time as this since the motorcycle cop hadn't reached her. She couldn't have taken it before this because the motorcycle cop would have been even further away. And she couldn't have taken it after because this arrangement was a fleeting thing that was not repeated. Hence, I don't see any basis by which the Moorman photo could have been taken by Mary Moorman.