A possible term is 'counterchange pattern':
"Patterning in which a dark motif on a light ground alternates with the same motif [in] light on a dark ground." (lexico.com)
The Frisian artist M.C. Escher famously made extensive use of this type of pattern, inventing a lot of new ones.
Take a look at his work Metamorphosis ...
I would call your example a square spiral. Most people wouldn't think of it as it two overlapping identical shapes. Rather, they would think of the black spiral as the one shape. The nearly-identical white shape is simply formed by the negative space outlined by the black spiral.
To find more complicated spiral patterns, have a look at search results for ...