When you are in the creation part of your album, you can zoom in on the pages to better see the texts, the background details or others. It's very easy. You just have to click on the + at the bottom right.
To zoom, you will simply need to click on the plus. Conversely, to zoom out, you will need to click on the minus. A small framed thumbnail will appear to show you the area of your album affected by this application. You can move the blue rectangle to focus on the part that interests you.