How was this pose done?

I think it was a melee picture. Might have been a reloading one, just go to a custom game, reload, melee. Then go into theater and mess with the camera till you get the pose.

 

Might have had something to do with crouching or jumping aswell.

 

I knew at one point, I believe its crouching + beginning to reload then melee

 

Its done by lowering your weapon offline

 

"Kill shot! That's a kill shot!"

 

Well have you tested any of them?

 

Its not done by lowering but by meleeing and reload simultaneously.

Video of weapon lowering, includes sniper
YouTube- How To Lower and Raise Weapons in Halo 3 (Machinima)

 

You're so wrong its funny, I'm 80% sure the way I said is correct, if you really want to know I can find out for you.