What do I mean by this:
I think this one’s pretty self explanatory.
How does it manifest:
There are a lot of ways. If it’s a story from the constrict’s point of view, this can be explicitly stated in various ways. The principal can observe it, whether in their own thoughts or outloud. Tone of voice and body language can do a lot – the constrict’s voice can shake, or they can be shuddering, or answering questions so quickly they stumble over the words, or nodding very quickly and making hurried assurances, or hesitating perceptibly before doing or saying something the principal might find upsetting. There can be the idea that the constrict is trying very hard to obey the principle exactly and being very careful not to anger them.
Divergent subcategories:
To me, this kink divides into two very distinct types: ‘the constrict is afraid of the principal’, and ‘the constrict is afraid of the principle, but __’.
The latter involves things like ‘the constrict is afraid of the principle, but still defiant’, ‘the constrict is afraid of the principal, but trying their best to control it’, ‘the constrict is afraid of the principal, but still won’t give them the information they’re after/compromise their morals/etc’.
The former is just about fear, period. It’s more likely to include more of the tone and body language manifestations described above. The latter is much more about the constrict feeling fear because the principal is scary, but not letting it control them.
To me, this is a very significant division. The two feel different to me, and I like them in very different ways. In one rather major distinction, the ‘fear, period’ dynamic is not one in which I like focus on the principal actually physically hurting the constrict. It’s more about scenarios like giving orders, walking down a hallway while everyone cowers, etc. If the principal does hurt the constrict, then it should be for some outside reason like being so angry they hit the first person they see, or doing it for the benefit of some other party.
Also, I very often enjoy this dynamic ‘in the background’ of a scenario – perhaps the principal is showing a newly-captured constrict around their domain, and meanwhile we see that all the servants are terrified of them.
Meanwhile, the ‘afraid, but __’ dynamic is one that appears in some form in most of the negative power dynamic scenarios I enjoy, I definitely do like it when it involves the principal hurting the constrict, and it’s much more likely to apply to the ‘main’ constrict in a scenario.
Actionable counterpart:
I’ve roleplayed a mildly ‘afraid, but __’ dynamic, and enjoyed it. Roleplaying a more severe version appeals to me.
I’ve also roleplayed a ‘fear, period’ dynamic, but in a format where my character was the main constrict, and was being physically hurt. I enjoyed this too. This might be an example of what I talked about in “a distinction in kinks” wherein I’m more flexible about physical elements being combined with various dynamics in scene than I am in story.