Rastafari was originally a Jamaican take on biblical teachings and spirituality, but it evolved into more of a cultural thing, then blew up in popularity because of Bob Marley (mostly).

You’d find Rastafarian stuff at most hippie or beach shops in the 90s and 2000s, then it sort of disappeared from the zeitgeist after people started stressing about cultural appropriation in the 2010s (hence the guy in the comic who thinks it’s problematic).