I've seen these picture before.
I thought that they weren't that bad, but according to an artistic friend of mine, they are really bad. He actually takes lessons in art and everything.
Now take a careful look at the paintings. They seem boring, don't they?
These pictures, at least according to my friend, lack contrast, focus, and shading. Now, go to the picture of the buildings. Notice the man walking near the right of the picutre. Then, notice the chimneys. See how the shadows are pointing in different directions? The whole shading in the picture is messed up, and it looks like the light is coming from an extremely low angle. However, in the picture, it is daytime.
In summary, Hitler was a terrible arist, which only contributes to the fact that he was a terrible person in general.