This is not funny, it's just a bunch of characters labelled with their defining features. It's funny in the same way that the following picture is funny:
|which is to say not at all|
Essentially the author has said "here is a collection of things I know about, if you're cool you will know about them to and laugh because I have stated facts about them". The comic strip currently has almost 3,300 shares and 5,200 likes on Facebook so people also appear to be buying into this concept. They appear to be laughing at it to show they are also cool and sending it to their friends who are doing the same thing as the picture spreads like a virus of stupid hipster bullshit.
|here we see said virus multiplying via mitosis in host cells|
So what we have is something that is 'funny' but isn't actually funny at all; it's simply a barrier to entry. If you get the joke you laugh and are let into some kind of conceptual club on the internet. But it's not a good club, the music is shitty and everyone is wearing Joy Division T shirts that are too big for them and pretending to enjoy themselves.
So why does this bother me? I don't enjoy clubbing - conceptual or otherwise - and I don't need to laugh at unfunny things to prove anything to anyone so why am I annoyed? Nerdy culture references done right in the real world are a great way for shy people to instantly connect with one another. You hear someone say something or see a specific design on an accessory or piece of clothing and a new line of dialogue is instantly opened up. One of the first times I actually talked to my current girlfriend was at a costume party when we were both teenagers because I was the only guy there who knew she had come as Link not Peter Pan.
Millions of quiet people make millions of first time connections because of this kind of thing; the internet has taken something that's a force for societal good and used it as a cheap excuse for lazy humour. What was once a tool for inclusion is quickly becoming one of exclusion and that's the real joke.
Stay Crunchy Internet
PS. It appears this entire post decrying hipster bullshit boils down to "I was doing something before it was cool and now everyone else is doing it and it sucks" wow... Irony's a bitch.