The flatbed picture plane replaces the window
From the Renaissance through Abstract Expressionism, pictures assumed an upright viewer facing a vertical surface that stood in for a view of the world. Beginning with Rauschenberg and Dubuffet, the picture surface began to work like a horizontal receptor, such as a tabletop, studio floor, chart or bulletin board, on which objects, images and data are laid down. The picture's reference shifts from nature to culture, and it stops imitating vision and becomes a surface for gathering information.