This feature is very helpful and important for your working process. After you make any changes in presets settings, they are being displayed instantly in a small preview window located under the Preview Area.
Hence, when you adjust controls, you will see what direction a generated image changes. This creates the effect of animation. Once you finish adjusting a parameter, an image generating for the Preview Area will start. It may take some time and depends on the complexity of an image, the viewing quality and the configuration of your computer.
During the generation of an image for the Preview Area, a progress bar and a percentage of completed processing will appear below the Preview Area. The progress bar looks like a blue thin line.