Beyond being a navigation tool for the E Ink screen, the touchscreen has an on - screen keyboard for data input (such as for searching or for adding notes) and colorful cover thumbnails that you can scroll through; if you flip past the list on the E Ink screen above the touchscreen, the E Ink screen moves to the next page to catch up with where you are in the LCD. (macworld.com)
You can optionally download the Kindle cover thumbnail if you'd like the ebook cover to appear in your library. (standardebooks.org)
Whatever the cause, book cover thumbnails routinely lagged behind the page load of the rest of the content. (pcworld.com)