Just as Donald Judd defined the term “minimalism” in sculpture, the south Texas horizon defines it in landscape.  Now that the town of Marfa has become a destination point for art aficionados looking for the root of Judd’s austere aesthetic, the trappings of haute couture have followed.  The Prada display of high-heeled pumps in an urban window sits smack dab in the middle of the empty landscape like a glowing ember of irony to the minimalism that surrounds it.