Fine Art Photography Historicals: Pictorialism vs. Modernism

This post is inspired by a slide that Maria Harper uses in her class Photographic Art History at Langara College. These images, both taken by Alfred Stieglitz, clearly show Stieglitz's transition from Pictorialism into Modernism.
Compare the atmospheric qualities of From the Back Window from 1915 with and the bold geometric shapes of Looking Northwest from the Shelton from 1932.

From the Back Window, 291, 1915

The way the eye is drawn into this image through the use of depth and a foreground path-like element contrasts nicely with the second image's unyielding two-dimensionality.

Looking Northwest from the Shelton, 1932



Looking Northwest from the Shelton seems to trap the eye within the frame using the oppressive lines of 30's era skyscrapers. The lack of a foreground path into the image minimizes what little depth is in the photograph and references the medium by drawing attention to it's inability to show true depth.
It's important to note that Pictorialism as a style became outmoded around 1915 and so From the back Window, 291 does have some very modernist aspects.