Final answer:
Robert Mapplethorpe's self-portrait challenges notions of representation on a conceptual level, aligning with the principles of conceptual art that values ideas over formal qualities.
Step-by-step explanation:
When evaluating Robert Mapplethorpe's self-portrait and its challenge to notions of representation, we can surmise that the challenge is not so much formal but rather conceptual. Conceptual art, which emerged prominently in the 1960s, often seeks to prioritize the ideas and meanings behind the work over traditional aesthetic values or material aspects. This movement was, in part, a response to formalism and a shift from the physical object to the conveyance of philosophical or emotional content through the artwork. Mapplethorpe's self-portrait can be seen as part of this tradition, challenging viewers to look beyond the visual representation and engage with the conceptual underpinnings of his work.