For example, if they are rude to a waiter or taxi driver, it may be indicative of their pent-up anger.
This is a signal that they are a demanding and emotionally abusive person who will one day turn their anger on you.
Emotionally healthy people who have done some sort of personal development, by contrast, show a quiet confidence that says they can be intimate and committed despite their flaws.
Emotionally unavailable people tend to be perfectionists, always looking for the fatal flaw or character defect that gives them permission to exit a relationship and move on.
Often these people "do" charming (as opposed to "being" charming) and are adept at communicating and appearing enthusiastic and enthralled. Their focus is on short-term intimacy, appearing to be open, revealing and vulnerable. Their relationship break-ups are never because of their behavior or the problems they created.