They schtick of the announcer, the sound effects... just the whole bit. They know their fanbase and pander to them.
It has a sort of, "Let's get ready to ruuuumble," 90's Jock Jams vibe.
I've been to many games in many stadiums, and I'll say one thing for the experience they've designed up there; it's unique.
Also, they need a true 2nd level concourse with restrooms and food. In their race to add seats to try and compete with BYU, they created an incredibly tight, underserviced experience.
I've attended two games there (last Saturday and a Pac-12 game a few years ago), and thought the same thing both times. It's crazy to try and squeeze 50k+ people into a stadium without adding restrooms and other services.