Powered by the bull market of the '80s and a post-Hippie embrace of materialism, yuppie symbolized a new style of consumer.
Merriam-Webster's definition "a young college-educated adult who is employed in a well-paying profession and who lives and works in or near a large city" doesn't convey the emotions (envy, scorn, etc.) the label generated.
The term was also a source of amusement.
As Time magazine asked, "Who are all those upwardly mobile folk with designer water, running shoes, pickled parquet floors and $450,000 condos in semislum buildings? Yuppies, of course ..." (January 9, 1984)
Image from The Yuppie Handbook, Long Shadow Books, 1984