The current movement to integrate arts within STEAM education is relevant not only for responding to complex societal and economic problems of the twenty-first century, but in that it carries its own sets of processes, questions and paradigmatic shifts that decentre dominant discourses in education. This chapter argues onto-epistemologically that arts uniquely engender a “mutuality” of disciplines constituted in the intra-actively entangled production of new knowledges through knowing and doing enactments within STEAM (re)configurings. It argues this is a form of critical intradisciplinarity. This chapter, which draws on an exceptionally significant data set, reports a novel analysis of a sample of drawings called “math-artworks”. These were created by South African young people in Grades 8–12 following a series of mathematics-art-experiential workshops. Theoretically framed by posthuman feminist new materialism, the chapter diffractively reads three of these drawings. It asks what matters in mathematical-art drawings by using Karen Barad’s concept of diffraction as a methodological practice for reading these drawings as data. The chapter uses diffractive reading to evaluate what it is that “math-artworks” advance, as encountered in the material enactments of South African young people. It also asks whether these configurings of intradisciplinary knowledge making generate new pedagogic repertoires. It argues accordingly that STEAM is a form of critical intradisciplinarity that is capable of activating future-making education.