In the past, when a head coach in the NFL threw a red challenge flag, the referee went under the curtain in the replay booth to see the play from a variety of angles, many which the fans could not view. When the refs emerged, you knew one team would be disappointed by the decision, and sometimes wondered what those guys were looking at.
Now, according to a story in the National Football Post, the fans will see the exact same replays that the guy in white stripes will see. The stadium video boards will show what the refs are looking at in real time, meaning whatever view the refs are watching will appear on the stadium's screens.
In the past, it was up to the home team to show what it wanted to. This led to home teams showing a favorable call over and over to rile up the fan base, but not showing a replay that might hurt their chances of having the call stand. For those few who are not fans of stopping the game for replays, an SI.com story says that instant replay added an average of one second to NFL games last season.