When a person is tagged in a Facebook photo, it shows up on their wall and in their photos, and adds an alert to their news feed. The image also shows up in their friends' news feeds.
One of the most popular ways to interact with friends on Facebook is by tagging them in images. While people use this function to tag images of their friends, it is also used to share information. If there is a popular quote that a member wishes to share with a specific friend, the person posts the photo on Facebook and tags a friend, who then gets a notification about it.
When a friend is tagged in a photo, that person has the opportunity to set security settings so they can approve any tagging before it shows up on their wall. Facebook members can untag any photos that they do not like.