On the one hand, the notion of mixed norm spaces has attracted considerable attention in fields such as harmonic analysis and PDE. On the other hand, a particular modification of the Bernstein operator, the so-called Bernstein–Kantorovich operator, has been of special interest for the approximation of the classical Lp-functions. This note has a double purpose. First, we record some elementary approximation properties of the Bernstein–Kantorovich operators on the mixed norm Lebesgue spaces. In the second part, we construct self-referential (fractal) counterparts to the functions belonging to the mixed norm Lebesgue spaces and introduce fractal operators on these spaces. With the help of the Bernstein–Kantorovich operators, we obtain a fractal approximation process on the mixed norm Lebesgue spaces. Furthermore, using the multivariate Haar system, we provide a Schauder basis consisting of self-referential functions for the mixed norm Lebesgue spaces, which we call the Bernstein–Kantorovich fractal Haar system.