You can arrange the way pages appear in the Comic Life window.
If you don't see the pop-up menu make sure you have the Page view visible by choosing View->Show Page View.
One Up: Presents the pages above and below each other.
Two Up: Presents two pages side-by-side on the screen.
Fit Width: Scales the document to the width of the view. You can stretch the Comic Life window to fill your screen, or make it short or narrow. Choose Fit Width to view all the content on side-by-side (Two Up) pages.
Fit Page: Fills the window with a single document page.
Note: You can have two-up mode show facing pages by checking the "Facing Pages" box on the Document Inspector.