But in statements posted to his Instagram account, he took a different tone. He said that the photo of Judge Jackson had been “misinterpreted” and was a “random photo taken from the internet.” He also claimed that the image of cross hairs was the logo of the website where he had found the photo.

Mr. Stone told The Washington Post, meanwhile, that the symbol near Judge Jackson’s head was a “Celtic symbol.” And on a broadcast with the conspiracy site Infowars, he referred to the image as an “occult symbol.”

The Instagram post was not the first time Mr. Stone had transformed his court proceedings into a spectacle. As he emerged from a courthouse after his arrest, he threw up his arms in Richard M. Nixon’s trademark double “V” sign.

Reached by email on Tuesday, Mr. Stone said that he had no comment beyond his additional Instagram posts and that he planned to attend Thursday’s hearing.

Last month, Mr. Stone pleaded not guilty to felony charges in the investigation by the special counsel, Robert S. Mueller III, into Russian interference in the 2016 election. He was charged with obstruction of justice, witness tampering and making false statements.

Mr. Mueller’s indictment accused Mr. Stone of lying to investigators for the House Intelligence Committee, which is conducting its own inquiry into the Russian election interference campaign, and of pressuring another witness in that investigation to lie to the committee.

The indictment also said that Trump campaign officials dispatched Mr. Stone to make contact with WikiLeaks during the summer of 2016, when the website was releasing a trove of damaging information about Hillary Clinton that had been stolen by Russian intelligence operatives.