For the page shown in this screen shot, I have customized the first of my four pages by adjusting the background color with a Hue/Saturation adjustment and adding some simple shapes. Photos can be changed out simply by dragging and dropping new photos into the document. On page 4 of the creation shown here, I deleted an empty photo placeholder and resized the remaining photo to fill the page. Elements resizes the photo from the original so there is no loss of quality from repeated transformations.
Frames can also be changed by dragging a new frame onto the document from the new Artwork and Effects palette. The palette also includes new drag & drop elements for your creations such as backgrounds, artwork, shapes, special effects, and styles. It's also easy to add and delete pages from your creation if you decide you want to add or remove photos later. New pages can be based off the original theme, or they can inherit the design from a page you've customized.