The trial is taking place in the U.S. District Court in Denver, Colorado, as the claim is over $75,000 and Swift and Mueller live in different parts of the country. Mueller was removed from the concert after security guards tracked him down, and Swift's team gave the photo to the station.
Swift countersued, alleging sexual battery by Mueller.
Mueller was sacked in June 2013 after Swift claimed he put his hand under her skirt while taking a photo with her backstage.
In a July 2016 deposition, Swift specified that Mueller had reached under her skirt and grabbed onto her "ass cheek".
After the photo was taken, Swift alerted her security staff, who confronted Mueller about it.
The jury questionnaire says anyone who is uncomfortable with discussing any instances of inappropriate touching can speak to the judge in private.
Swift wore a white dress with a black jacket on Monday as the eight-member jury is chosen from a pool of 60 prospects. There will be no alternates.
Potential jurors were asked where they work, their educational background, and marital status, as well as if they work in the music industry.
The trial is expected to last about two weeks. Neither side is expected to settle. She says she wants to hold Mueller accountable and is seeking $1.
Swift and Mueller aren't required to be in court for jury selection, which is expected to end Tuesday.
Mueller and his girlfriend lined up backstage with other fans for a meet-and-greet with Swift and entered a curtained enclosure where they spoke briefly with the singer-songwriter.
"It's impossible for me to pick one specific moment that it was happening because it happened in a series of moments, so one of the moments when it was happening, in progress, was the moment we were posing for the photo and when the photo was being taken, but that was not the only moment that he was grabbing my a**", she alleged.
Swift is countersuing, claiming sexual assault.
Mueller denied the allegation and asked that they call the police. He and his girlfriend were escorted out of the arena and a member of Swift's team called his boss. "Swift. Mueller never sued KYGO for breach of his employment contract", reads the singers response. She tried to keep the situation "discreet and quiet and confidential" and was upset by Mueller's claim that "for some reason she might have some incentive to actually fabricate this story", her attorney, Douglas Baldridge, has argued in court. Mueller's attorney says his client may have been misidentified after someone else touched Swift. "Swift, Mueller intentionally reached under her skirt, and groped with his hand an intimate part of her body in an inappropriate manner, against her will, and without her permission", Swift's countersuit filed in October 2015 reads.