Because it is new - It was not bought - it was a commercial loan. It was played for a short video review, and the total play would be less than any ukulele on a rack in a store would get. Some of the ukuleles I review get sent back to the store / brand and then are sold to the market in shops. Should the brands be selling those on as 'used' because they featured in a short video? If so, some of the biggest UK uke stores have been selling a LOT of ukuleles that way.. And that inlcludes Kala, Koaloha, Baton Rouge, Magic Fluke, Blackbird, aNueNue and many more.
In addition, some ukulele stores will loan people instruments on approval so long as if they dont buy they are returned in mint condition. Those instruments will then be sold new also.
If I sell a ukulele that was bought by me and was mine, they are sold as used.