For teachers, Incognito Mode can be a valuable tool for a variety of reasons. Incognito Mode makes it quick and easy to check out how things will look and function in Google Classroom from a student's point of view. I use the Incognito window to login to a generic student account that is enrolled in my Classroom and see exactly what my students will see and how they will interact with the application. Check out the short video below to see how this can be done.
Incognito Mode can also be used as a simple way for students to login to their Google Accounts on a teacher station for quick tech help, to print, or to do anything they need to do without requiring the teacher to logout of his/her account.