There are a few different search results related to a "mystery gift" in the context of Nespresso, so its unclear which one you are referring to. However, based on the first search result, it appears that Nespresso may offer a mystery gift as part of a promotion. According to a Reddit post, in October 2022, Nespresso offered a promotion that included free shipping and a choice of either a blanket made of recycled coffee grounds or a ceramic mug as a mystery gift. Its unclear if this promotion is still ongoing or if there are other mystery gift offers from Nespresso.