punctuation - What does the dash ("—") in this sentence do?

Does "–" between methods and documenting have any function in this sentence? What is it trying to say?

Moreover, multi-lingual texts, like vernacular works, have traditionally had strong affinities with realist methods – documenting speech forms as they are spoken – but avant-garde, musical, parodic, sci-fi, psychic-interiorist, artificial/invented, machine, and digital multilingual works have also long followed non- and anti-realist logics.