The media section of your profile publicly showcases all the images and embeds you've post to your profile.
To add media, you may either attach it to a wall post, or manually add it to your media page. To do the latter, click on the "Add Media" button, and select the type of media you want to add. Then either paste in the link of the media, or browse your computer for the picture to upload. Click "Save" when you are ready to add the media to your profile.
To view a media, click on its tile on the Media tab. The media will be shown in a lightbox. When you are done viewing the media, click on the green "X" near the top right of the screen.
To delete a media, hover over the media you want to delete and click on the red "X".