The familiar, made grotesque
Our reading of the mackerel pair: the ordinary fish is what gives the wrongness somewhere to begin.
Grotesque Mackerel is an aberration of Blue Mackerel. Set beside its original, it invites a different sort of looking: not just what is strange, but what remains familiar.
To our eye, this is the pleasure of the pair. The original gives the aberration a point of departure; keeping both in view makes the transformation more interesting than treating the stranger as an isolated trophy.
The two entries keep the same two-slot footprint, Coastal habitat and daytime window in The Marrows. We read that continuity as part of the unease: the changed creature still belongs to the same small piece of a fishing day.