Nope. The head is distorting but from ear to ear stays consistent. It might be undersized by no more than 1-2%, which is far less than the body is oversized. Here is the proof. I scaled the same photos relative to Oswald's leg length instead and applied the same algorithm.
There is only 1 conclusion I come to, and that is CE 133-A was shot with a different camera than the rest. Otherwise, the spherical aberration of the lens and quality of this photo clearly does not match the others. Oswald immediately claimed it was a fake, which probably meant a darkroom creation where a print of CE 133-A was photographed with Oswald's Imperial Reflex camera. This camera was not originally found with Oswald's possessions by the DPD. And this is not to be confused with Oswald's Minox spy camera or his superior 35mm Russian Cuera 2 camera, which was probably the camera that took the original CE 133-A.
This along with all the other shenanigans that the DPD where up to in the darkroom, including re-enactments and a curious cutout of CE 133-C, which was never submitted into evidence nor found with Oswald's possessions, makes the BYPs highly suspect. The fact that the DPD only leaked CE 133-A, which was the money shot where you could actually read the name of the commie lit, means they were an integral part of the conspiracy. They sheep-dipped Oswald to be the patsy with the BYPs, planted the gun in the TSBD, arrested him in record time, interrogated him in private and took no notes, then led him to his assassin who did the killing for them to gave them plausible deniability. This is why they didn't kill him in the theater. I could go on and on but you get the picture. 
Your gif is not taking into account the wide-angle effect. In the original prints CE-133A and CE133B we see that Oswald was in differing parts of the frame and subsequently was affected by the predictable lens distortion.
In the following gif I applied approximately the same lens correction to CE-133b as seen in CE133a.
Even though there is a number of parallax changes between CE 133A and CE133B the following comparison shows the stairs and the fence and etc to be almost aligned.
Now when we take into account the wide angle effect and the differing positions of Oswald and Marina we see that Oswald's head when in the same position of the frame becomes the same shape and he is the same size.
Btw are you sure that there is different lens distortions in the backyard photos?
JohnM
