Alice Stoehr’s review published on Letterboxd:
In the plant and animal kingdoms, certain predatory species have evolved so that prey will perceive them as harmless or even alluring. This practice is known as "aggressive mimicry." As Wikipedia informs me, it's employed by species as varied as the anglerfish and Venus flytrap. So far as I (a human being) can tell, this tendency has no malice to it. It's inborn, often part of of the organism's anatomy, and used for the sake of sustenance. Only through the crudest guesswork can I project human morality onto this kind of survival tactic.
It's the same way with the thing (entity? creature? "alien"?) played by Scarlett Johansson in Under the Skin. It hunts and snares a number of young Scottish men, and its actions are related onscreen through short, matter-of-fact scenes that build into loose chains of cause and effect. The film applies no judgment to the thing's behavior, nor does it provide a whit of exposition to supplement Johansson's studied blankness. Instead it exacerbates every inch of horror with this gap in our understanding of the creature—and, as the plot's gradual pivot suggests, in its understanding of us.
The feeding process depicted here looks so monstrous when you can't see any motivation behind it. No anger, no hate: just a nightmarish lampooning of earthly sexual politics blotted with Mica Levi's strident score. Eroticism, this cornerstone of cinema, is teased apart as Johansson flirts, strips, then walks into what seems like an infinity of inky, reflective blackness. It's ritualized, aestheticized, weaponized, turned back against the subject by the erotic object, and all with a tone of haunting detachment.
In Nymphomaniac, I noted an explicit reference to the motion studies of Eadweard Muybridge; here, the same observation is perhaps more of a reach, but I can't help seeing it in that last nude walk through the chamber. As in those images of slow-motion figures, here there is something basic and remorseless, something in Under the Skin that's molding science fiction toward a definition of human life. Here is art with the possibility of connection or discovery that's still terrifying in how it lays us bare.