To create an image that is not harmonious, an artist could

To create an image that is not harmonious, the artist could:

1. **Change the proportions of the facial features so they no longer worked together** - This would create a disjointed appearance, making the face look unnatural or exaggerated, which is often used in abstract or conceptual art to evoke a feeling of disconnection.

2. **Change all organic shapes to geometric shapes to create a cubist portrait** - While cubism itself can be harmonious in its design, by deliberately manipulating the forms and creating jarring combinations of geometric shapes, the artist can produce a sense of chaos that disrupts the viewer’s expectation of realistic representation.

The other options, such as using a shading technique that blends highlights and shadows seamlessly or using patterns of color in the background to emphasize light showing through leaves, are typically harmonious techniques. They aim to create balance and cohesion within the artwork.

Therefore, the most effective techniques for achieving a non-harmonious composition would be the first and the third options mentioned above.