Because there are only so many ways you can pose with a gun:
Stock Pose
Number of Occurrences
The Oscar Mike- You've got places to go and faces to shoot. An extra thousand points for every Black Hawk or Abrams in the background.
19
This is my rifle. There are many like it etc. - A classic pose that somehow always leaves the soldier looking agitated with his current predicament. Covers only one half of the box, usually leaving the other open for explosive scenery.
20
Sean Connery is about to shoot you - The game is taking you hostage and the fourth wall will not rescue you.
18
Pistol Pose - I guess we all know who to blame for this one.
25
The Ominous Look Back - I'm not sure if Dudebro™ is angry with us or just camera shy.
10
John Woo Presents - Because putting dual-wielding on the back of the box isn't enough.
6
Triple Threat - Charlie's Angels have got nothing on them.
8
Oh Look, A Squirrel! - Apparently, you & your mates have found something really intriguing off-camera and can't stop staring & pointing at it.
