What does this mean if after alj. When asked for an update they say its sitting on the judges desk this was 1 month ago?

It might mean that the judge is still looking it over getting ready to sign off on it and then send it to the decision writers.
Then they will write up the decision and send it back to the judge to sign off again.
Atleast that is how mine was done and it took about six months from the time it went to the judge and to the decision writer's and back.
I am still waiting on my award letter.
I wish you luck.