No he can't. He isn't party to the trial.
The only way he can be held in contempt is if he got rowdy in the courtroom. Outside the building, though? The judge is powerless.
But Trump can be called for violations of the gag order. The order says that he cannot induce others to attacks the judge's family either. Having his surrogates show up and lie to the American people is a violation of Trump's gag order.