Kids, parents of kids & former kids who attend / attended a Waldorf or Steiner school, a movement of schools founded by Rudolf Steiner (the first was in the Waldorf cigarette factory in Stuttgart)
in the early 1900's. Lots of the photos one finds of Steiner are a bit severe looking, but rumor has it that he was a hottie, and he may have been taken less seriously by other adults had he wandered around looking like a clown. There are a bunch of Waldorf / Steiner schools in the US as well as other places in the world. Some Waldorfians are hippie-esque in their lifestyle aesthetic & many are
tree huggers (amateur or pro), but some are movie stars (who may hug a tree from time to time), and some are even
Republicans. The whole idea is that you're eventually supposed to think for yourself instead of copying everyone else, whoever they are at the moment. Being called or referring to yourself as a Waldorfian can be positive or negative depending on tone and whether referring to what's consistent throughout Waldorf Education (e.g. fairy tales told in
kindergarten) or a quirk of a particular school's culture.