You need to keep in mind that marketing renderings are generally done before materials/suppliers have been selected and finalized. Renderings, even for an architect, show ideas. They do not take the time to model each and every particular product, with the exact final shape/dimensions/etc., so much as represent the space.
I'm not defending the lack of honesty in the renderings, but that's the way it works in the industry. Regulating something like a marketing image (which does have disclaimer a disclaimer attached pointing out that it's an artist's depiction) would be very difficult since often, even in an architect's renderings, it speaks to ideas ("a large round pendant lamp hanging here") more than it does to final products and selected suppliers ("the _____ Lamp produced by the company ________"). Those details can't possibly be resolved by the time the building goes into marketing.