I write this assuming I'm ISTP.
ISTP: Ti Se Ni Fe
If I take the shadow of each function and reverse the order, I get INFP.
INFP: Fi Ne Si Te
INFPs are attractive, but I don't understand why they do some of the things they do, particularly when it comes to people. If they are happy, they can be quite pleasant, and I often find myself wanting to give them a hug. If they are unhappy, it's like they're surrounded by this vacuum of negativity, and I want to avoid them at all costs.
On the other hand, if I keep the order of the functions the same, I get my shadow function, ESTJ.
ESTJ: Te Si Ne Fi
I don't know any confirmed ESTJs in real life, but they seem to take themselves quite seriously. I get the impression that they don't exactly color outside the lines, ever. I can respect their dedication, and they might be useful as co-workers, but I can't imagine I would ever interact with them outside of a work environment.
If I keep the functions as-is, but reverse the order, I get ENFJ.
ENFJ: Fe Ni Se Ti
One of my ex-girlfriends claims ENFJ, so I have a little more experience with this type. She was quite fun, and would always be up for an adventure, but IMO was overly concerned about feelings. After a while, I got tired of her constantly needing that kind of affirmation (no, I don't hate you just because we haven't talked all day). We are still friends, and I think the relationship works quite well on that level.