>Portugal (the latter is located between China and Japan for mysterious low-dimensionality representation reasons)
could that have a real world reason given that Macau used to be a Portuguese colony as well as Brazil hosting the largest Japanese diaspora population in the world?
Unlikely, because virtually nobody in Macau speaks Portuguese anymore, and Reddit is not well known in Japan. Various Japan-related subreddits are very popular, but they're populated by English speakers living in Japan, travelling to Japan, etc.
Seems to be pure chance. r/brasil and others are in a very different place in the graph, and none of the subreddits related to r/portugal are connected to any of the Japanese/Chinese subreddits in the graph.
could that have a real world reason given that Macau used to be a Portuguese colony as well as Brazil hosting the largest Japanese diaspora population in the world?