My thoughts aren't a lot different than DLAs. Like him, I'd be more inclined to belly crawl till I was at least under 100 yards from them.
A lot of factors that could be critical to a clean kill are not shown in the picture. Also, you didn't mention what caliber, or whether it's with open sights, or a scope.
Since you're basically asking us to pick though, I'll set up a possible situation where I'd take the shot.
First, because it "is" an elk, and therefore requires a good bit of thump to bring him down cleanly, I wouldn't be using my 1894C 357 LOL! I'd feel perfectly comfortable though with a 45-70, 444, or other comparable caliber with the proper load at that range. I also wouldn't be scoped, because I hate scopes on lever actions.
I'd look for a rest, like a tree, or something to steady my rifle. If none were available(and stalking was out), I'd settle into my sitting position with my elbows locked into my knees. Then I'd wait, as neither of those bulls are presenting an actual "clear" shot. Both of them have fairly heavy grass blades in front of their vitals, and the grass appears to be a few yards away from the elk, which is even worse about causing the bullet to veer way off course.
As for taking the shot with the animals positioned as they are, either is deadly in my book.
My preference is the quartering towards me shot on the right. With that shot, I'd put the bullet where it would just chip the front of the shoulder blade, and plow through the front of the left lung, the heart, and the back of his right lung.
With the turning broadside shot, I'd drill him right through the shoulder, back into the vitals.
The elk on the right would likely drop in his tracks as the bullet busted the off shoulder. He's standing with most of his weight on that shoulder, and his head is also gonna weigh that side down being turned the way it is. He'll also likely try to run the direction his head is pointing at the shot, which will help the other factors even more.
The other elk will likely run a ways before he falls. The shot would bust the facing shoulder, but like the other one, he's standing with more weight on the off shoulder. The way his body is turned, he'll easily recover from the initial shock of the bullet hitting him, and then run a good ways on three leggs, even with the vitals destroyed.
My observations are only made by comparing what a whitetail would do under the same circumstances. Maybe elk react differently, but that's my thoughts on the picture anyhow.