just silly reference to already pretty dated slang terms. c.a. 2016 it was popular to describe things which were exciting as "lit" and speak to friends as family, shortened as "fam"
One could say "it's lit fam" meaning wow exciting things are going on here, hey guys! but in a more literal sense of the words australia is infact lit. on fire. (ex: what's up? the sky. hahaha not funny)