If you see a broken image or a red X, then it's possible you're using a remotely linked pic that no longer works (the other site that hosts the image is down, has deleted the image, or has stopped supporting remote-linking). Please see:

What happened to the option to, "Link to an online image?"
http://help.xanga.com/profile-linkedpics.htm

If you just see no picture at all, but you think you had one there before, then it's possible you *deleted* or changed the picture you originally used.

To fix it just click to edit the post and click to "reset" your profile pic. Then you can just click "Submit" to use your default pic or click "Choose »" to choose a different one.