All these files add load time to the page and can interfere with the page’s compatibility with some internet browsers, particularly the infamous Internet Explorer. The following is how to convert the original image and additional files into one image files thus reducing the number from a possible maximum of 7 files down to 1.
1 - add the image file to the page.
2 - add the frame, drop shadow and reflection via the Inspector/Graphic pane.
3 - with the cursor select and copy the photo and all the enhancements to the file.
4 - open Preview and select File ➙ New From Clipboard.
5 - select the image in Preview’s Sidebar pane and drag onto the iWeb page.
Preview in Snow Leopard
Preview in Lion
6 - remove any frame or stroke from the new image that the iWeb theme may apply to it.
7 - the end result will be a single PNG image containing the frame, drop shadow and reflection.
This iWeb/Preview tutorial was created from information garnered from posts by several users, Roddy, Wyodor, Koeklin, and others, in the iWeb Discussion forum.
NOTE: This method does not work on images in iWeb photo or album pages. It applies to only those photos the user had dragged onto one of the other page types.