Sudo /Applications/Install\ macOS\ Sierra.app/Contents/Resources/createinstallmedia -volume Select the following line by dragging your cursor from just prior to the word sudo to past the word volume: Make the Finder's Applications window small enough so that you can see it, the Terminal window, and the USB drive icon, all at the same time.Also, the Install macOS Sierra app must be present in your Mac's Applications folder, otherwise the pathname won't be correct.Its name isn't important because createinstallmedia will change it. Make sure its icon is present on your Desktop.Format the USB installer as Mac OS Extended (Journaled) and GUID Partition Map.To create a standalone installer on a USB flash drive or similar removable media, refer to the following instructions: Create a bootable installer for macOS - Apple Support. Perhaps you will notice something different than what you have been experiencing. The following is the procedure I use and illustrates what you should see.
