Since the 1980s she has taken up a feminist position as a response to the Cologne art scene dominated by men like Martin Kippenberger and Albert Oehlen. As co-publisher and editor of the music magazine Spex and as reviewer and staffer for other influential journals like Texte zur Kunst, Flash Art, and Artscribe, she has made a significant contribution to the development of art criticism and the discourses of German pop culture. Koether’s creative work is linked thematically to the »great narratives« of art history. She follows an agenda of »restitution through repetition,« of reparation through appropriation and recapitulation, in order to emphasize the importance of female (co-)authorship. In the 1990s she aroused interest with works like Cézanne, Courbet, Manet, van Gogh, ich (Cézanne, Courbet, Manet, van Gogh, and I, 1990) or Ganz (100 % Malerei – Niemand ist eine Frau) (Entire [100 % Painting – Nobody Is a Woman], 1991), with which as a young woman artist she made her mark in the male-dominated tradition of modern art. Using irony, she challenges the iconizing of the old masters and the cult of genius that has existed since the German Romantics, and jolts the self-image of the (male) artist with disenchanted and humorous comments.
Her very personal style of painting is characterized by an overlaying of fine layers of drawing and painting usually in striking red. In her early works, by integrating everyday objects and using the fake glitter of »poor« materials (foil, tinsel, metallic paint) she created a kind of trash-chic aesthetic, which alluded to the glitz of the new millennium and criticized the capitalism of the 2000s as empty glamour.