Images and Documents are stored with your web pages on a staging server in the CMS. Think of them as your working copies. They must be published in order to be used on your web pages.
Depending on user access, you will either be able to publish your images and documents or you will have to submit for approval to an administrator.
By default, all users can publish content, but this may be restricted if the website was created with administrator oversight. If you are unable to publish but was not informed about this feature by a website administrator please submit a request.
Publishing images or documents follows the same steps as publishing a web page. For help with this visit How do I publish a web page?
Every time you add a new image to the CMS server or make changes to an existing image on the server you will need to publish it before using the image on your page.