Without viewing the pic, the likelihood of a vendor substituting a D. villosa or D. ascendens** for a D. adelae is single-digit probability at best.
Looking at the pic, the lateral ridges along the center of the leaf blade and the thin sides of the the leaf are both much more indicative of D. adelae than either of the others mentioned. The small amount of petiole present is consistent with D. adelae I am currently growing.
** whether or not it is "correct" to separate out these plants, I don't really care. Imho, the worse evil is done by pretending they are still the same when both knowledgeable people viewing them in the field and others who have grown both - see them as two distinct entities. Personally, I have grown both and easily observed larger differences than often separate Nepenthes species (I know - since I'm taxonomically ignorant, my view is worthless - but that doesn't mean I don't have one)