the film touches greatly upon the theme of self-destruction. any human who has experienced depression in their life has been inside of the shimmer. i like to believe alex garland sees the shimmer as the place a person is when overwhelmed with feelings of isolation and dread. it is a space that confines you, scares you - but where the inner-workings are wondrous and beautiful. the old adage for artists is to use your feelings of existential dread as the fuel for your art. this could be one reason the shimmer is depicted as a place of undiscovered beauty while being the horrifying, crawling catalyst of everything that happens in the film - and what is ultimately happening is change.