All magnas are double yellow headed amazons, but not all double yellow heads are magnas. Magna double yellow heads, if I’m not mistaken, are not just called so for their extreme yellow head colorations but also for their very specific native range and not all experts consider magna to be a valid subset of the species. There is another DYH with extreme head and wing coloration too called the tres marias double yellow head, also from a very specific native range. While the bird in those images most certainly has greater than average yellow on its head and red on its wings, there is no real way to distinguish whether it’s a “magna” or a “tres marias” or a hybrid or simply something of a freak of nature who hit the genetic lottery for DYHs.
Edit: if you curiosity stems from the fact this bird commands a higher price than a regular DYH, I would say it’s fairly irrelevant what it’s being sold as, clearly it has exceptional and highly desirable colorations and will therefore command a higher price regardless.