Here is a scene with characters in dynamic poses. They look alive.
Here are some characters in static poses. 1) evenly spaced apart
2) Standing straight up and down
Fred and Barney's poses have strong lines of action and they have different degrees of action - they aren't in the same poses. Barnet's pose is stronger-he is leaning back on a diagonal line of action. Fred is on an arc that leans to the right at his head. the space between them is creating a V shape that leans to the right.
Here is Wilma in a pose. She isn't standing straight up and down. Her pose tells us her attitude and what's happening in the story.
Here is Ranger Smith in a static pose next to a cook in a subtly dynamic pose. Dynamic poses don't have to be extreme in every case. The pose should be appropriate to the scene, character and story. 
ACTION AND REACTION: 
This is obviously a publicity shot - and those are usually kind of bland and generic for some reason.
Here is another static evenly spaced group of characters from a comic.
Compare to a more lively couple of poses.
Fred and Barney's poses have strong lines of action and they have different degrees of action - they aren't in the same poses. Barnet's pose is stronger-he is leaning back on a diagonal line of action. Fred is on an arc that leans to the right at his head. the space between them is creating a V shape that leans to the right.Again to drive this home...here is a static line up of characters who have no poses. They are all vertical and evenly spaced.
Here is Wilma in a pose. She isn't standing straight up and down. Her pose tells us her attitude and what's happening in the story.
Here is Ranger Smith in a static pose next to a cook in a subtly dynamic pose. Dynamic poses don't have to be extreme in every case. The pose should be appropriate to the scene, character and story. Here is a nice frame that shows Yogi in a very subtle pose, his body very slightly leaning back and his head cocked subtly away from the man. The other character has a stronger more definite pose leaning forward; they aren't mirror images of each other.
ACTION AND REACTION: This is a good technique for scenes when 2 characters are talking to each other. Usually, when one character is doing the talking, his pose is more dynamic that the other's.
But also, the character doing the listening is REACTING to the one talking. Boo Boo's pose is leaning back in a less extreme arc than Yogi is leaning forward. Yogi is the cause, Boo Boo is the effect. Yogi's forward pose is pushing Boo Boo backwards.
Dynamic poses are much more entertaining than static poses and when used in context, they tell the story better. The last thing you want in animation is to have characters just stand there reading dialogue.
Next: more action and reaction.