While browsing through the Bauhaus archive site, I was particularly attracted to this postcard circa 1923 by Paul Klee, called "The Bright Side." I found it fascinating because it contained what I observed as elements with different levels of abstraction, which related to what we have learned about Gestalt principles in accordingly various ways.
At first glance it - like many of the Bauhaus works we have seen - appears to be a configuration of different colored shapes and lines. Triangles, squares, and circles in yellow, red, and white stand out against a light blue background. Under closer inspection, aspects of the image begin to arrange themselves into discernible figures. We may achieve recognition in respect to the top third of the picture first, because it appears to be the least abstracted aspect. Here, Klee departs from the limitations he imposes upon himself in the rest of the picture to only use triangles, squares, and circles in favor of more complex forms.
What emerges from our perception of this rectangular-like shape appears to be a building or temple, with the double blue rectangles in its center representing the doors, the yellow lozenge shape at its top representing the roof, and the the words "WEIMAR" at its top and "BAUHAUS" below indicating its identity as a structure related to the Bauhaus School in Weimar, and perhaps even the Bauhaus School itself.
That this portion of Klee's postcard is less abstracted guides our attempt to decode the rest of the picture. As I studied them, various interlocked shapes below the building began to fuse into something like a stacked tower on top of which it rested. An interpretation that dispenses with the traditionally Western desire to see objects depicted with perspectival realism could find, in place of the tower, a long pathway leading up to the building's front door, with the variously colored shapes standing in for different colored stones that one might find in an old-fashioned street.
The high level of abstraction in this part of Klee's picture allows us to manipulate it quite freely, seeing it alternately as a pathway and a tower, while still being able to mentally reduce it to its most basic, abstract elements. It takes more work to reduce the building, which Arnheim would identify as possessing the essential structural skeleton that allows our minds to quickly process and understand it, despite the fact that it does not realistically resemble any building that we know of.
A more complete abstraction of this aspect of the image may be obtained by turning the whole thing upside down. Seen in this way, the structural skeleton of the building becomes invisible and the words surrounding it illegible; thus we can't see it as anything but a purely abstract collection of shapes.