Images that are in .jpg format can have different color types associated with them. If you have inserted a .jpg file and all you can see is a broken image, the .jpg file is likely using the CMYK color mode, which may not be supported in the browser you are working with. At the present time, Internet Explorer is the only browser observed to experience this issue. Some email programs like Microsoft Outlook are also affected by this issue, making it important to save images using RGB colors due to its popularity.
To resolve this issue, open the .jpg file using a graphic editing tool and change the image attributes so that RGB color mode is used instead of CMYK. You can then upload the new image and it should show up correctly.