Anvil and Mirror

The Julia set of the alternating composition, one Burning Ship half-step z -> (|Re z| + i|Im z|)^2 + c followed by one Tricorn half-step z -> (conj z)^2 + c, at fixed c = -0.406102557 - 0.438939394i. The fold depends on z only through x^2 and |xy|, so the four seeds with either sign flipped share one orbit and the set carries two exact mirror axes, whose crossing is the centre of the frame. Luminance is a ridge in the log distance estimate, so sub-pixel distance reads as dark plating.