If what you see is either off center, or leans in a direction (especially if the background trees do not lean), then movement or action is indicated. Note that portraits typically do not lean. All these three things might be summed up by the word "composition."
A very smart English museum-tour bus driver told us that if you fold a picture of a painting into sixteenths, then unfold it, each of the sixteenths should more or less make the painting "happen." For example, look at a picture of Rembrandt's "Jeremiah." Each sixteenth pretty much goes with Jeremiah. The fact that he's off-center and leaning diagonally means he's an action figure. Probably he's worried about getting his "Lamentations" into the editor by the deadline. Perhaps he's forgotten where he lost his shoes. Again.
I won't fold Rembrandt's "Night Watch" into sixteenths, though you can easily see that each piece "fits." Note the diagonals on every figure but the central one: muskets and pikes, persons, dogs and chickens are going or looking somewhere, as a night watch crew should. The gent in the middle is clearly the watch commander - vertical lines and central position connoting strength.
Rembrandt's picture of this old geezer, a Rembrandt self-portrait, though, veers from the rules. He's off center and pointing diagonally, meaning he's into action. Cripes, he's older than I am, and clearly going nowhere because of his arthritis or leg cramps. This goes to prove that there sometimes is no point in the rules.
You should also do some research, or at least half-useful Google-clicking to take an intellectual trip through art history before heading out to the museum:
