First, snobbism is based on the idea of superiority. Superiority, in itself, is banal. There are people taller than others, those who can bench-press more, or have more hair. Some have finer palates or are handier with a wrench. Human superiority comes in thousands of varieties, and almost all are completely trivial, since the worth of a human being is not based on randomly selected measures of talent, wealth, or good fortune.
So snobbism must somehow transform something trivial into something important and existential. That is point two. I have better taste in music than you, say, but can bench press less. So what? Or reverse those positions. The snob has to feel that some particular (arbitrarily) set of these measures of "superiority" is meaningful, even when it is not.
Thirdly, snobbism must work by some kind of "shorthand." You cannot thoroughly outline the merits (or lack of merits) of someone, so you rely on a convenient shibboleth. "The kind of people who..." They might pronounce a word a particular way that reveals that they are "lower class." Or listen to music you don't approve of. Remember that the concept of shibboleth comes from a test of pronunciation. The shibboleth is trivial, by definition. It marks the person as belonging to a class not to be bothered with (or to exterminate, as in the biblical example.) It is a trivial marker of a trivial distinction, or a trivial difference given existential weight.
Snobbism (and this is the fourth point)hides behind an aesthetic pretext. I don't despise those people, the kind that gives their kids names like Tyler, but just regret their lack of good taste, says the snob. We know the snob is hypocritical, because he or she will tolerate other kinds of ugliness quite well.
#5: Although it seems to be an individual position, one based on the superiority of the self, it is really about the group with which the self is affiliated. The self hides behind his or her membership in the club, whether this be a race, a gender, a class, or some subset of cool people. It is a form of insecurity, since someone confident of his or her talents and good fortune has no need to mark trivial distinctions so emphatically.