This summary is not the rule. The rule text controls.
If someone is charged with a crime that could lead to the death penalty, and the court decides the trial needs to move to a different parish because a fair jury can't be found locally, this rule gives the court another option. Instead of moving the entire case and trial to that other parish, the court can go there, pick a jury from that area, and then bring that jury back to the original parish where the case is being handled.
This matters because moving an entire capital case to a new location can be expensive and complicated. It means transporting evidence, witnesses, attorneys, and court staff. By allowing the jury to travel instead, the case can stay in its original court while still giving the defendant a jury pulled from an area where they're more likely to get a fair and unbiased group of jurors.
The judge decides whether to use this option. It can happen either because one of the parties asks for it or because the judge decides on their own that it serves justice better than the standard approach of moving the whole trial.