If you would like a list where you can browse among the different categories you check the box "Show category browse feature" and selects the metadata definition chosen in step 1.
You will see all the images in the folder selected who are tagged with the metadata category Flower.
If you click on a miniature there will be a detailed description where you see more information about the image and can download the different image sizes. You can get the image right off or add it to a cart in order to download all desired images at the same time (in a zipped file).
If you do not want the option to browse on categories you do not check that option. Then there will only be a search portlet where you can search for metadata like category, file name or other metadata connected to the image.
If you have other metadata connected to the image e.g. photographer you can search for that as well.
If you would like the metadata value to be shown in the detailed description of the image the check box "Render in HTML as <META>elements" needs to be checked.