The way I understood it is a commercial for McD in the US isnt required to have real food; a commercial for McD's "whatever" has to have the actual item being advertised, but can be so meticulously crafted, you'd never see one like that in the wild. A commercial for a grocery chain, for example- most/all of of the food you see is props made to look like the most appetizing food youve ever dreamed of.
Who knows if this is enforced. NPR and PBS stations are specifically prohibited from "sponsorship" messages mentioning a specific product or service, and they've been ignoring that for decades.