The best way to explain Human or Story dynamics would to explain dynamics as a whole, so I will in throw references to systemic dynamics as well.
There are a lot of metaphors that I like to use to explain Dynamics, but my all time favorite is "the game." In a game there are always these two principles, the goal is to win, and there are a set of rules or parameters that must be addressed and applied in order to win. These principles are also existent in Dynamics, although the rules of the game change depending on what dynamics we are looking at. To play the game of Human dynamics, you have to dance to a certain tune, or play by certain rules. The rules of the human game are composed of etiquette, social norms, rituals, charm, diplomacy, charisma, and so on and so forth.
If you are an INTP, then you are probably retching at all of this, because this is a game that we generally dread playing (assuming we didn't make the rules). Like any other game there is a way to play it right and a way to play it wrong. Playing it right elevates your position in society, more friends, more money, higher paying job, more stuff, etc. Playing it wrong penalizes you by lowering your position in society, lose friends, lose your job, do not pass go do not collect $200.
Now overlapped on top of a Society and human dynamic, are systemic dynamics. The rewards for playing the the system right are extremely similar and sometimes the same: higher paying jobs, more money, more tangible success, etc, etc.
Now then, there is something very crucial that I need to point out. A Society, or a corporation for instance are already made Human and Systemic dynamics respectively, but that is not all dynamics are, Societies and Corps are just two examples, two games among an infinite sea of potential games. A new game can be made at any time.
To have a dynamic, all you need to have are rules/parameters, and there are rules and parameters to everything. In a systemic dynamic, rules are based on logical principles, for instance, if you are not strong enough to kill or flee from the bigger animals, you get eaten, and lose the game. In a human dynamic, rules are based on value principles, for instance, if you cheat on your girlfriend then it demonstrates to her that you do not value the relationship, so she breaks up with you... and you lose the game.
These rules are subject to change at any point in time, when new rules are introduced. For example, because of our advances in civilization, we our system works on different rules than the wild, and we don't really have to worry about bigger fish eating us (literally speaking) so the principle about needing to be physically strong to survive does not really apply to us. Similarly there are many cultures that share mates, and having other sexual partner is completely normal and would not be considered a deal breaker. Dynamics are not static, they can be changed, and new ones can be invented.
Now then, I bring in the word "Values" because in feeling functions, agreeable and disagreeableness is equated to "good" and "bad" respectively. What makes something good or bad depends on values-based the criteria. In the case of Fi, this criteria is personal, and in the case of Fe, this criteria is universal. In human dynamics, playing the game wrong might just get you labeled as a "bad person." For instance, according to the universal rules of our culture, on Mother's day you are supposed to give your mother a call or a gift or whatever. So according to cultural norms and etiquette, if I neglect to do that, then that means I am a bad son, (She is an ENFJ, so she totally would totally think that too.)
I bring in the word "Story" because I wanted to outline another principle within the principles of values based criteria. Every person has a story behind them; we all have goals, we all have dreams, we all have fears, we all have a history, we all have a future, we all have baggage, we all have loves, hates, talents, sensitivities, etc. Fe in the most simple and yet accurate of words, is in essences the dynamics behind how stories interact with each other. Fe is a function that allows you to influence the stories of others, by influencing their loves, hates, fears, etc, and it can also allow you to read into a person's story. When a person looks at you a certain way, or has a certain inflection in their voice, or if they neglect to say hi to you on the way in, it tells you something about their backstory. It tells you thing like what they want, and why they want it. Are they happy, are they sad, do they like something, or do they dislike something, etc. With Fe we are able to both move and interpret the stories of others.
I am going to take this a step further and say that humans are not the only ones that have stories. There is a story to everything, in the exact same way that there is a system to everything. There is a story to the clouds, There is a story a squirrel, There is a story to an H202 molecule, There is a story to the gods, There is a story behind the Universe.