When you add images to your slideshow, they need to be sized correctly; otherwise the slideshow will be slower and the images won’t look centered in the viewing area. This instructional video shows you how to size the images to exactly 300pixels wide by 260 pixels high using a free online tool, “pixlr.com“.
NOTE: you can also do this in photoshop or in some other photo editing software such as Gimp or “pixelmator” (MAC).