What are the grey margins on the pages for?
The greyed out border along the pages and the cover is known as the bleed margin. The bleed margin in every page indicates the portion that is likely to get trimmed when the album is made.
When you position your photo or text very close to this margin, we''ll auto-align them with the edges so as to get a full bleed spread, i.e., to spread the photo or text out till the edge(s) of the page.
The photo or text will be placed over the greyed out margin and aligned to the edge(s) of the page. There''s a chance that a marginally small part may be cut away from your photo or text at the edge(s) of the page. Anything between 0-3mm can get trimmed from the sides of the pages and 0-10mm from the covers.
But if you do not want any part of your photo or text trimmed, please avoid placing them very close to the grey margin.