Cornyn is reading them the riot act about implying impropriety on the part of the judges for testifying.
Here's what Scotusblog said about it
4:58: Senator Cornyn points out that Alito has disagreed with his colleagues before so there is no reason to think that their testimony today could lead to a conflict of interest. He points out that sitting judges providing testimony like this is not unprecedented.
4:55: Sessions points out that Congress messed up Rybar, not Alito. Laughter (agreement?) in the room. Sessions is asking whether or not throwing rocks at people is a federal crime. Lots of chuckling. Judge Lewis points out that rock throwing could be a civil rights violation.
4:53: Senator Sessions remarks that Alito's civil rights opinions have almost always been unanimous.
4:53: Senator Durbin is up and agrees with Senator Leahy on the inappropriateness of questioning sitting judges. Senator DeWine has no questions for the panel.
4:50: Senator Kyl is asking for clarification on the 3rd Circuit's policy of distributing 3-judge panel opinions to the whole court. Not every Circuit does this.
Judge Scirica is clarifying. They only circulate precedential opinions, or non-precedential opinions with a dissent. Therefore precedential opinions are sent to the court twice - before and after publication.
Kyl is asking what happens if a Judge disagrees on the initial circulation. The Judge can write to the opinion writer or the entire court expressing his/her disagreement.