New Fashion Aesthetic

I’m reading De Botton’s The Architecture of Happiness at the moment. Its discussion of the things that determine taste has lead me to wonder what it is people find appealing about the New Aesthetic. A lot of the discussion about it is very cerebral. “What is it?” etc. What I’m interested in is: why do we find it interesting / beautiful / etc. Because after all, “There are as many styles of beauty as there are visions of happiness.”