Visible crew/equipment: In the opening close up shot of the eye, you can see a reflector screen reflected in it. (00:04:10)
Character mistake: Early in the film we are repeatedly shown the alien character flirting happily with various men, relaxed, confident, even socially forward, in fact often more articulate and socially at ease than the various Glaswegians she encounters. Yet later on, inexplicably, all this social nous mysteriously disappears and she is completely baffled and blindsided by the simplest of social interactions, almost a mute. Since the film has virtually no plot it's hard to see why this jarring turnaround should be so.
Female: So, why do you shop at night, then?
Deformed Man: People wind me up.
Female: How?
Deformed Man: They're ignorant.