Federal judges (should) have a lot more decorum and patience. Actually all judges should have, but the US also popularized the mini dictators that dole out ridiculous punishments for "misbehaving".
People in court are not there because they bought tickets to the venue for their own enjoyment.
While I agree Trump should also have some decorum, he is effectively rich trailer trash. The judge treats him as such and in my book that makes the judge an icon.
The judge is above his petty nonsense but does take the time to make trump feel he is not in charge every time he steps out. And I think this is far worse for Trump's feelings than being stuck in a holding cell, that would just fuel his martyr syndrome.