For me, one of the beautiful subtexts in the movie was Adams' remembrances of dreams of horses, where it wasn't explicit whether it was the aliens expressing th

For me, one of the beautiful subtexts in the movie was Adams' remembrances of dreams of horses, where it wasn't explicit whether it was the aliens expressing the images to her, or she was summoning the feeling of communing with another being, using that experience as a tool to open her mind to what the beings were expressing to her. It captured the feeling of synesthesia very well. Between Arrival and Interstellar, the potential of movies to express incredibly complex ideas with new visual metaphors seems to finally be coming into form.