In this case, agency or spa (client) pays MediaCorp to use the artiste for the shoot. Hence the paying party owns the rights to the photos. The photographer who is in turn paid to do the shoot is just a "contractor" hence owes no rights to the photos. And when MediaCorp finds out photographer uses the photos for his or her own purposes. MediaCorp will demand the removal of the photos failing which they will sue. Also even if agency or spa does not sue you, you can be assured you will be blacklisted by agency.