If you are an Admin, you have the ability to preview the reviewer/judge portal as if you were a reviewer.
To login as one of your reviewers/judges:
Click the "Management" button on the lefthand bar
Click the "Manage Reviewers" page
Select "Login As" next to the reviewer's account you would like to sign into
This can be useful when trying to solve a problem that you are unable to replicate with your Admin account