Update —
I contacted Prohosters via their online chat option, and they helped me out. The problem, according to them, was that I had hot-linking disabled, which is (apparently) why people can’t go directly to an image like through the links Classics posted above. If you click on those links now, they should work (they do for me, at least).
Now I’m curious about when you (Classics) viewed the actual site itself, without going directly to the images. Did that also give you problems? Because if it did, if the graphics didn’t load on the main page, then I don’t see how enabling hot-linking would solve the problem. Even if hot-linking is disabled, I think the images should appear on the pages anyway (they have for me and for others who have viewed the site). Now, with the hot-linking option enabled, I feel like I’m susceptible to bandwidth leeching.
Classics, can you please check my site once more and let me know if the images are appearing correctly for you now? Thanks again for your help.