Zoom View is a feature in select NOOK Comics that lets you zoom in on a single panel and read a book by moving from panel to panel by swiping or tapping.
If you see the Zoom View button at the top of the screen, tap it to zoom in on a panel. You can also zoom in by double-tapping on a panel. To move to the next panel, tap on the right edge of the screen or swipe from right to left. To return to viewing the entire page, tap the Zoom View button again or double-tap anywhere on the page.
You can also enable Zoom View Letterboxing by bringing up the Reading Tools menu and tapping on the Settings icon. Enabling Zoom View Letterboxing hides adjacent panels while using Zoom View.