After launching, Diffusion captures an image of the current viewport of your model in the Preview pane.

Diffusion uses that viewport as the original input for any generated output. After generating output, generated images will appear in the Gallery.

The Gallery contains all images generated during the current Diffusion session as well as any created within the past 30 days. Images are arranged by date in expandable menus. Any image you have liked will appear with a thumbs up in its preview. Click any generated image and it will appear in the main Diffusion window. From there you can further refine your image, or click Add Scene to add it to your model.