The resulting image, then, consists of all visible and hidden files and the drive’s unused space. Even if the source USB drive isn't bootable, you still need to make a clone if it has more than one partition. You need the drive's master boot record and partition tables too.
The difference here is that you simply can’t drag-and-drop its contents to another USB drive. This guide targets users who need to fully back up or clone a USB stick, such as a USB boot drive. Take the usual drag-and-drop method in File Explorer to transfer files to and from the USB stick. Don’t follow this guide if you’re simply copying files from a USB stick.