Final answer:
The "flatbed picture plane" represents a conceptual shift in visual art, emphasizing the surface of a painting as a flat plane for composition, which played a critical role in the development of Cubism and modern abstract art.
Step-by-step explanation:
The term "flatbed picture plane" refers to a conceptual shift in art where the surface of a painting is treated not as a transparent window into a three-dimensional space but as a flat surface on which objects and shapes are arranged. This concept significantly changed art, as seen in the works of Picasso, Braque, and other Cubists who combined multiple viewpoints, light sources, and planar constructs to present their subject matter in novel ways, often confusing the foreground, middle ground, and background.
The flatbed picture plane thus contributes to the abstraction movement by emphasizing the canvas's two-dimensionality and the formal arrangements of shapes and colors upon it. Artists like Richard Diebenkorn integrated this idea into their work, seeing landscapes as a series of flat planes that resemble a flat design or an irregular grid, as seen from his aerial perspective.