From the viewpoint of logic, this film doesn't make a lot of sense. But taken more emotionally and imaginatively, it's quite clear what the issue is and how to resolve it. Somehow this poor lady lost her family, and she'd been in such mourning that she contemplated offing herself via an overdose. Until she stumbled on a golden opportunity: not only to serve her purpose and end her pain, but also to save earth and humanity. If we were to compare Always the Sun, with feature length sci-fi films such as Gravity or Arrival, then this short film falls way short and is bound to disappoint us terribly. But I don't think that's a fair comparison, to begin with.
The two genres of filmmaking don't just differ in terms of length (quantitative), but in structure, "tools," and intent as well (qualitative). Short film, in particular, has to rely much more on such things as emotion, metaphor and irony - in a highly compressed storytelling: She gives up her life, in order to save the lives of billions; she dispenses with conventional methods of suicide, and agrees to a novel, colossal alternative instead; she ends her terrible sadness, while helping scores of people feel happy. So while Gravity or Arrival is a novel, Always the Sun is a poem. In this light, it's a deft, wonderfully evocative film.
I love the imagery, the soundtrack, and the acting. Margot Mount is a beautiful actress, to be sure, and even without much dialogue to work with, she underpins, for me, the emotional impact of the film - her eyes and traces of tears, her expressions in two very different circumstances. Kudos to Rob McLellan!