Looks to me like they were saving the last row for something ... weird how everything else is packed except one row.
Those seats are for the press who take photos at the start of the program right at the front of the stage for a few minutes. They get to take some photos and then they have to go back to those seats.
The news cameramen probably kept that clear so people wouldn’t walk in front of the cameras. The brunette lady with the bun hairdo was probably there keeping folks out for that reason