Gestalt psychology is an important concept for artists, and it's one way that the struggle of order and chaos is part of good design. The Gestalt effect is also built into everyone, so you can expect audiences to respond exactly the same, regardless of age, gender, or culture.
Your brain makes sense of things by forming relationships between the objects in your field of vision. When these relationships are all equal (in the first image, even the blank spaces are similar in size to the circles), your brain has to constantly work in an attempt to organize the field. In the third image, your brain easily categorizes the shapes by proximity, value, and size. Clustering the circles into groups and the colors into gradients makes this sorting even easier.
Strangely, in Gestalt psychology, too much order feels chaotic and organic disorder feels more controlled! This idea can be incredibly useful in painting. An artist with a good understanding of Gestalt effects can visually engage an audience without overstimulating them, helping them be open to the ideas his or her art is trying to express. I'll talk about some specific Gestalt principles in later posts, so stay tuned!