The Pussycat Doll and worldwide recording artist was spotted hanging out with the 21-year-old next to the yoghurts at a store in Swindon.
Douglas worked at Asda before auditioning for The X Factor earlier this year.
Pictures taken by customers of Scherzinger's surprise career change have since appeared on Twitter and Facebook.
The 'Don't Hold Your Breath' singer last week dressed up in a latex corset to serenade another of her acts, Rylan Clark, at his birthday party in London.
Speaking to Digital Spy yesterday (October 30) at the Cosmopolitan Ultimate Women Awards, Scherzinger said donning the outfit was "the most fearless thing [she's] ever done".
She added: "And I think it's pretty fearless to move someplace I've never lived, away from home and give it a chance - and take a chance on my contestants and the shows."
Scherzinger - who also mentors James Arthur - is currently the only X Factor judge to have not lost an act during the live stages of the competition.