Your index file just specifies a slideshow with dimensions of 480 x 360 with this line of code:
var so = new SWFObject("monoslideshow.swf", "SOmonoSlideshow", "480", "360", "7", "#ffffff");
If you want a larger slideshow, you have to define a larger window. imageScaleMode = "scaleToFill" tells Monoslideshow to fill the defined view window with an image, not to fill the screen.