#Really Shouty Man
Atleast its not https://t6.rbxcdn.com/d7dc8c6da1b1e4f41f2ba7a71def3d9c I'd rather have shouty man lol
i can only assume battle cry is supposed to raise your spirit and fear the enemy? or its just dragonball z style. shouting = you get stronger and ascend (eventually, after 17 episodes)
For the first image, Its suppose to put a sense of "Action" In the game, even if its about as boring as taking a shit.
For the second image..
idk
Maybe they wanna show how good their dental plan is?
Bearing your teeth is a primordial instinct to signal that you're ready to fight. When you make that face it unsheeths your canines - or it would if we still had that biological function. Same with goosebumps. They're supposed to stand our fur on end to look bigger and scare other people.
The function is still there, we just lost our fur.
they all stepped on a lego at the same time.
never forget
If someone were shouting like that in your vicinity, you'd probably check it out, right? Now, imagine if you saw a picture of that person shouting on the front page of an article. You'd likely have a similar curiosity. It's not a conscious thought process, it's more of an instinct to check out why someone is exhibiting the extreme emotions behind their shouting.
How could you leave out the king of screamy guy faces? 
screamy guy face.
SPOON!
Would you rather dull surprise?
Morgana just looks like she's snarling or gritting her teeth.
Looks more like he's smiling than screaming to me.
you forgot
[maybe more too tired]
physiologically represents action
Most movie covers are the same. Actor + 1 item to designate genre. White guy with gun next to face for action.
they are just preparing for their boyfriend (to smooch vigurously)
I think Zac’s just smiling