> What interests me about this Finnish subculture is that it's perfectly cloned the "horse culture", just without any actual horses. It's very close to a cargo cult. Possibly Finland is too cold to have a regular horse culture?

There is a horse culture in Finland, and as you said, it's heavily associated with teenage girls. Horses are of course quite an expensive anf time-consuming hobby by definition, so I'm sure the affordability plays some role here too.