View the original community article here
Last tested: Aug 28, 2018
models-user-X directory does NOT act as a "pointer" to a permanent local copy of the shared branch's files. Instead, when you create a new shared branch in Looker, a branch on the remote repo is created; this branch contains all of the commit history for the branch. Then when each other user enters the shared branch in dev, they fetch from the one, central remote repo, creating file copies from that repo in their
models-user-X directory (and deleting the files for the branch they switched away from).