That guy has not only been blitzing his shoulders with heavy weights for god knows how many years, he has been taking some serious AAS and hormones and eating bountiful amounts of good clean foods - when you team that with fantastic god-given genetics, appropriate muscle receptors and large muscle bellies, you see for your own eyes the result...
To say that this guy looks like that mainly because he has got himself lean is simply ridiculous!
I've been training hard and eating well for over 20 years... and the amount of guys who I have seen with shoulders like that, are few and far between.... and I have seen thousands of 'lean' guys.
Again, I'm not saying that just anybody would have shoulders of that level simply from being lean. I'm saying that most people would be surprised at how much better their shoulders really are once in contest condition and that this guys shoulders would appear significantly less impressive if he was a more typical 13-18%.
Of course you would still need the genetics, drugs & work to get an equivalent level of overall appearance as the guy in the video.
Consider the factors you mentioned: Insertions (genetics), drugs, leanness, size
- Take away the insertions and they won't be quite as impressive, however you can still go decently far through the other factors.
- Take away the drugs and you will lose fullness/"paper thin" look but you can still get a decent look through relying on the other factors.
- Take away the size and you the impressiveness will be on a smaller scale, but they can still have "the look" based on other factors.
Take away the leanness, however, and it all falls apart. Sure you will still have big shoulders but suddenly "the gap" (open space between the shoulder & the bicep) is mostly gone, the striations do not show through and the muscle no longer appears to be pressing out of the skin.
Now of course it wouldn't work if you took away two or more of the factors at the same time, I'm only saying that you can "get away" with missing out on ONE other factor besides being lean, whereas being lean is the only one that can ruin the look entirely on its own.
That's why I say that leanness is the biggest factor overall: the other factors are all important, however you can still have what would be considered "impressive" or "the look" while missing one of them, just on a lesser scale.
Leanness, however, is the one factor which is actually a "requirement" by itself.