Without going into a ton of rant-esq details in my personal experience:
BOTH GROUPS
*have mommy and daddy's money to play with
*neither really have any type of work ethic.. IE, the expectation is you will earn $100K+ your first year out of school studying the migratory habits south American moths.. or by being an "activist"
*are used to being winners just for showing up
*believe themselves to be open minded but ridicule those who do not think exactly like them
*got all their news from Jon Stewart, and now from John Oliver
*stay on mom and dad's family phone and medical plan as long as they realistically can. Sometimes there are family plan benefits to this, I get that, but if you are 30 years old you shouldn't be having your parents pay your Verizon bill
*are perpetual students, some of the people I know half a half mil in student loan debt and are paying all sorts of crazy interest only partial payments, etc. These people will never pay these loans off, the only hope is that eventually someone bails them out (read, Bernie Sanders)
HIPSTERS differ from that group by trying to at least embrace some kind of "cool" identity (typically something perceived to be "manly", like lumberjack, beer brewmaster, repairing quirky old cars, listening to records, growing facial hair, smoking a pipe, etc.). What's strange is, this doesn't usually come from a genuine place (IE, they didn't grow up helping their father split wood on the weekends), but more of a "I'm rebelling against my other millennial friends", but at least the hipster crowd of the millennials brings something more to the table than just shallowness, and most of them work and are more industrious than just the folks spending mom and dad's money (one of my friends started two business, one making beard oil and the other as an outdoorsman hiking guide) <- I have to respect that