Miranda Cosgrove appeared to be a typical 15-year-old shopper — applying the latest flavor of lip gloss at the cosmetics counter — except most of the other Nordstrom customers on a recent afternoon weren’t accompanied by security guards and didn’t have the ability to make youngsters audibly gasp.

Cosgrove stars in Nickelodeon’s “iCarly,” a series about a tech-savvy teen who creates her own Internet show, which could be described as “Wayne’s World” for hip girls.

Further proof of the show’s popularity was on display at the Mall of America’s Rotunda, where more than 600 screaming teenagers gathered to get autographs from Cosgrove and snap pictures with their digital cameras and cellphones.

Cosgrove played the scheming sister in the hit Nickelodeon series “Drake & Josh,” had a scene-stealing role as the no-nonsense band manager in “School of Rock” and has a record deal with Columbia Records.

But during a half-hour shopping trip right before the autograph session, it was clear that Cosgrove is more or less a typical teen. She’s addicted to “The Hills.” She said she loves purple. And her worse nightmare is accidentally leaving her cellphone at home on Friday afternoons because she’s worried she’ll be left out of her friends’ weekend plans.