You might be wondering why some of the demo images are not showing up in your media library. This is because they are included with the demo as a reference point for you to be able to customize your theme easily. They are not meant to be used permanently unless you choose to download and/or purchase them on your own. If you do choose to use the same images, they are included in the uploads folder in your theme, but will not show up in your media library through WordPress unless you download them yourself for your own use.