I see a pose as a simple component of a skilled action. The pose identifies four parts that are required for skilled action. There must be an environment such as the stage that provides the context in which the action takes place. There is the physical structure of the actor doing the action. There are the joint angles that describe the geometric relationships between the elements of the physical structure.
At this point everything is static, there is no time.
I have greatly simplified everything, the stage, the body components of the actor, and the elements of the pose. However, all these pieces are directly observable.
The second section looks at the relationship between the actor and the stage, the actor's position. This is traditionally looked at through geometry and the physics of forces and momentum. I focus on a simplified geometry so that I can mostly ignore physics.