In addition to Corners and Embelishments, you can also add Stickers to your project. This is a fun way to decorate and further enhance your pages.
Once you have clicked to select a page to which you want to add a sticker, click on the Stickers option in the tool bar at the far left of the editor. This will open the Stickers sidebar.
From there, you can then either search for stickers by keyword, or select from various categories, such as Party, School, Music, and many others. Once you've found the Sticker you'd like to add to your page, simply click on it, then click on Apply Sticker.
You can then move or resize it however you wish. Explore the options and have fun!