Artists represent these things in many different ways depending on medium and style. Cubist artists use color and shape to create depth and emotion in their work. There are many different painting techniques to create texture and form. Stippling, and sponging are two examples of ways to create texture,
The answer is <span>Interpretation
When creating an artwork, artists often put his emotion, principles, or pollitical value into his artwork and does not give any information about it for the audience. When the audiences see the artwork, they would combined the artform that they see with their own emotion/principles which lead to the personal interpretation on what the artists actually want to convey.
</span>
this device is called the Oscilloscope.
an museum, art classes and art websites