Security Reminder
Local does a pretty good job of scrubbing private info from the logs and the errors it produces, however there’s always the possibility that something private can come through. Because these are public forums, always review the screenshots you are sharing to make sure there isn’t private info like passwords being displayed.
Reading through the article, I don’t think that the disk image is supposed to show up in Disk Utility, rather, the article indicates that using Disk Utility is a way to verify that the DMG isn’t corrupt.
Were you able to run the “Verify” step and navigate to where the Local DMG was downloaded?
Also, did you try re-downloading the DMG to ensure that there wasn’t an issue with downloading it form the internet?