To view pictures stored on a flash drive, you will need to connect the USB device to your computer. Once connected, you should be able to open File Explorer (on Windows) or Finder (on Mac) and access the files on your drive. You can then double-click any image file stored on the flash drive, which will launch an image viewer program like Paint or Photos in Windows 10. If desired, you can also select multiple images at once and drag them into another folder or application to view them together.