Drag an asset onto a tier to rank it. You can also tap an asset to select it and then tap a tier. Items reorder inside a tier, and you can send them back to the asset panel the same way.
There are three ways to bring in images: pick them from the image panel, drag and drop them onto the page, or paste them. Each way takes any number of files at once. Every image is cropped on arrival to the largest square its center allows, and becomes an asset. The tier panel sets each tier's name, color, text color, text size, and typeface, and reorders, adds, and removes tiers.
Double-click a panel title to switch how the panels are laid out. In the movable layout you drag panels wherever you like and keep several open at once; in the fixed layout a single panel sits in the top right.