This is a very interesting thread, kudos to OP!

Actually I've been thinking about this myself lately. Negative self-image of course manifests itself differently in individuals but trying thinking it from an INFJ perspective... Uhm, hmm. Hypersensitivity and seeing rejection as valid seem very likely responses as INFJ as a type is already highly hypersensitive. It would make perfect sense to try to assess people's intentions and views in the negative light and see everything as a sign of rejection (not able to see other influences to people's behaviour, people's own possible problems completely unrelated to INFJ, in words INFJ may lose sight of objectivity and start the vicious circle of blaming themselves for causing every single each tiny bit of a negative response in others)?
-> Could lead the INFJ with a low self-esteem into further isolation, to an imagined "rejection" from everybody possible. (depression, self-destructive behaviour etc)
Or/and everything and something in between denying their very own natures and trying to become something else (transform themselves in order to be accepted, liked, loved - whatever is the core issue behind the low self-esteem, or possibly even all of them) - which I think is unrelated to type, behaviour which we can see in everybody with low self-esteem and in extreme cases in narcissism.
The INFJ might be starving for recognition and like all "unhealthy" individuals try to "win over" people into liking them (that sounds harsher than I mean though, point being in at not valuing oneself makes one into seeking approval from selfish motivations to gain back their own "self-value"), especially with enneagram 4s might start building delusional fantasies about being special and misunderstood and try to compensate their low self-respect with leveling themselves up with that false image - "I am special and although others don't understand me, it's what makes me unique and different from everyone else, this suffering is all I have, it's my last resort and no one can have it, they're all fools/stupid/entersmthere"
With a low self-esteem a lot of shame is always buried underneath, a very difficult thing to deal with it.
Hmm I think there are very different routes to which it could develop in the INFJ, someone mentioned the ESTP shadow which could with enough stress and possibly depression (which low self-esteem usually correlates with) lead to.
I hope I made some sense at least with this but like could never be emphasised enough it's still individuals

And anyways, just my 2c. But I kind of think self-esteem is a very big and an influencing thing in a person almost as if in the background of everything the person does and is, and believe there are regardless of type, some common factors of how we deal with it with subtle modes.
Although I think it is potentially a devastating issue for the INFJ due to his/her introspective and introverted nature in the begin with, also believe it can be - possibly, some of the most rewarding processes to deal with it in course of life for the INFJ as it forces to face a lot of ugly truths in human nature to find the balance and the beauty in themselves and others and also appreciate it in ways a lot of people could miss because of its "get your hands dirty digging in there real deep" necessity, so I hope I'm not offending anyone with the abovewritten as I really think self-esteem as a process, not a given, stable condition - to some a bit more challenging one and to others not as much, but anyways just as a spectrum with lots of shades and variation and a part of the whole which we call the ego.