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

There's a site devoted to Oswald's time in Russia, and on the home page, they show the same passport photo of the guy with the bull neck. 

http://www.russianbooks.org/oswald-in-russia.htm

Presumably, he got that photo taken shortly before he went to Russia in 1959. So, let's compare it to an image after he arrived and got settled in Russia. Here's an early image from Minsk.

Again, we see that thick linebacker neck on the Oswald on the left, and a more delicate neck on the Oswald on the right. If we were talking about anything else but the JFK assassination, nobody would think they were the same young man. 

The neck is a part of your anatomy that pretty much results from your genetics. You might do barbell curls to build up your biceps, but very few guys put a harness on their head to do weight-lifting exercises to build up the neck. We're seeing two different men here. 

Even at a very young age, it was obvious that "Lee" was going to be a lot stockier and huskier than "Harvey". Tough luck, Kennedy-killers.