Hi there!
"The Judge without a courtroom", is a metaphor from a piece of English literature called "A Voice".
In the piece of literature, it can mean "Someone who demands a lot of respect". A judge, gets the respect of every person in a courtroom. But outside the courtroom, the judge may not be shown respect.
The father in this piece of literature, is like a "Judge without a courtroom", because he thinks he deserves respect.
I hope this helps you!
~Alexa