There are two types of items that you can add to your Profile: detailed and list. You can even mix and match these two types within the same Profile section.
A detailed item has a title and three more (optional) components: a single image, a text description, and a bookshelf attachment. When its section is set to show more detail in Profile view, the item's title and photo will appear if there is one, otherwise the item's title and description will appear. This is probably the item you will use most frequently – some may have a photo, others may have text, and others still will have both. It's entirely up to you.
A list item has a title and an unordered list of text. You cannot add an image, bookshelf attachment, or free-form text to a list item. When its section is set to show more detail in Profile view, the item's title and list will appear.