My J-nature is usually rears its head more when I sense chaos. But when I say "sense" I don't mean seeing a messy house or a messy desk. Those things bug me, but I seem to constantly have a messy house/desk (for me it's because I'm such a bad perfectionist that if I don't find the perfect place for it, it usually ends up on the floor). But sense is something different. The order of how things *should* be is out of place. Something doesn't feel right. And so I try to fix it by putting that out-of-order thing back.
It doesn't have to be tangible chaos, however - and I'm actually pretty rotten with physically putting things back. But here's another example. I'm in charge of a very small team at work. One of the girls is an ENFP and it's tough for her to get started on projects (and tough for her to finish on time). I'm usually pretty chill with her and give her plenty of time. But when the deadlines hit I can switch gears fairly rapidly. I suddenly start giving her task lists and I'll start emailing her every few hours to see how far she's gotten. Because it's not just about her anymore - it's usually about the team as a whole. Sometimes I'll take her work from her and do it myself because I'm not happy with how long it takes. Sometimes I want to be nice about it, but the deadline is more important at this point and we need to get crap done.
I tend to be more of a J in overall situations, or in situations that concern more than me. But when it just concerns me, it's usually less of a big deal and I can/do let certain things slide.
I've been accused of being bossy and of being too uptight, which have surprised me in the past because I never saw myself that way. The problem is, I'm too chill most of the time unless something important is coming up. Then I'm like...SUPER J. Which can annoy the heck out of some people.