Since the mid-19th century, fashion increased in pace and the art world went through a similar cycle of change. There was a crossover in thematic concerns between the two disciplines, from issues of identity and morality, to concerns over the way the artist or designer was perceived within the wider culture, and a greater focus on representation of the body. Fashion is occasionally cast as art but this is problematic. Fashion has its own particular concerns that prevent it from being purely art (or craft or industrial design). It is a three-dimensional design form that incorporates many elements. Fashion should be understood on its own terms.