Ahh, likely a common mistake. There are two primary causes of this problem.
1) Pictures are displayed in a web page by using a reference within the code telling the web browser where that picture “lives”. The problem may be that these references are wrong. Often when the site is built on your personal PC and you create references to pictures you create references to the pictures in various folders around your PC. To see if this is the problem, open your web page in your web browser. Hover your mouse pointer over one of the red X’s and right click. Choose properties from the menu that appears.
In the Properties window that appears look at the Address: (URL) line. This tells you where the web page is looking for the image. If this address says something like C:/something then the reference is set to the image on your hard drive. Correct this by going into the coding for your web page and putting the correct reference.
For example, if you have a directory inside of httpdocs called images or pics where you store all your graphics the reference would be /images/picturename.filetype. If your images are just inside of httpdocs the reference would just be picturename.filetype.
2) The second common mistake is in naming the files and references. Unix servers are case sensitive. This means that to the server picture.jpg and Picture.jpg are not the same file. In the properties window, check the case of the filename in your reference. Then compare that to the reference in your page code. If one uses capitals and one doesn’t that is the problem. Adjust one or the other so that they match and re-upload the affected pages.