I read once that Hitler tended to make scenes as they actually are (shown here), and focused a bit more on the creations of man. Notice how only one painting out of these four does not contain a man-made structure as part of the primary image. Another search (that I did five minutes ago) said that the person who rejected him said his art was "unsatisfactory" and lacked "spiritual inspiration." He focused too much on the created and not enough on the creator. He also struggled to draw people. This information could be false, so do your own research if this isn't enough. Sorry if I misled you, but this is what I understand.
