Social media just streamlined the process for a mindset that has been around for centuries. Instead of snapping a selfie people used to have to sit in a room for hours while somebody painted their face, which is arguably way more vain.
Each new generation of people is always dubbed "the worst", in reality though, we are all pretty shit.
Being narcissistic and setting unrealistic goals for yourself is definitely good advice. Millennials gonna millennial.
I realize it's hard to take that gif seriously, but that quote is actually pretty old and has nothing to do with millennials. It's a quote about having confidence and making sure that you let others know you have it.