[2] In December 2005, Ostojić became well known in Europe as a result of her poster After Courbet, L'Origine du monde, also referred to informally as "EU Panties"[3][4] The work, a satire of French Realist Gustave Courbet's 1866 painting L'Origine du monde, was first displayed on billboards at the public exhibition EuroPart held in Vienna in December 2005 – January 2006.

Along with other works from an ongoing art exhibition, this poster was selected to publicly promote Austria's presidency of the Council of the European Union.

[6] Vienna's Kronen Zeitung newspaper turned this selection into something of a scandal, expressing its outrage over state-funded pornography and its concern for Austria's world image.

From 2000 to 2003, she publicly addressed this issue in an online performance piece, Looking for a husband with a EU passport, in which she presented herself naked and with a shaven head, possibly reminiscent of a prisoner from socialist times.

[7][10][11] At the Venice Biennale in 2001, her performance I'll Be Your Angel involved her following around the independent curator and art historian Harald Szeemann – who had at his disposal a significant budget – for days, all the time simply smiling fondly at him.