Does marketing products claimed to be gold-plated silver, without certainty of the validity of this claim, and sending free pieces to unveiled and naked women for review and a percentage of sales, fall under the designation of pyramid marketing, and is working in it forbidden?

There is no harm in the girls to whom free samples were sent promoting the goods and convincing others to buy, and taking a commission from those who bought directly from the seller through them. This does not fall under pyramid marketing. Marketing is not forbidden merely because of the presence of pictures of immodestly dressed women, because this is something that has become widespread.