You get a number of filter previews, filling gradually. Each preview has a number of controls. If you hit the 'ok' button the associated filter is applied to the image. The 'sel' button gives you the opportunity to save the filter, or load a previous saved filter in its place. With the small slider next to each filter you can adjust the 'fitness' of each filter. This will influence a future generation of filters. This new generation is obtained by hitting the 'NEXT' button. With the 'PROP' button you can adjust the number of previews or change to another (or new) session file.