"caveat emptor" = buyer beware!
A basic principle in Western law.
It seems that advertisers are allowed to create impressions and associations, as long as they don't overtly make false claims. This allows them to dance definitions with the finesse of angels on points of pins.
In your example of "Blueberry Muffins" there are two logical legal escaper routes.
The first is that a name is only a name for the product, not a definition of what it is; it could just as easily be called "Muffy Blue". The second is that blueberry functions as an adjective to describe the muffin - thus it only needs to be blueberry-like to fulfil the consumer's expectation, and to meet the definition of truth in advertising... especially when the real truth is revealed in the fine print of the list of ingredients.
The real truth in advertising, or about it, is that sellers are not required to declare any adverse qualities about their product - for instance, that eating just one everyday would overload the body with far more sugar than most people ever need and lead to serious health problems in later life, or that the specific food dyes are toxic to some people, or that the lack of fibre and low glycemic index is a predictor for colon cancer.
Yet there is another truth. We need no advertising at all if we buy whole foods and make our own at home. It's cheaper, healthier and more delicious by far. And we can perceive directly with our own senses what we get while shopping.
I can't view the cited material but truth has always been rather flexible in advertising, the more so the less the intrinsic worth, irrespective of currency cost, of that which is being advertised.
It's led in the UK to quite strict laws on advertising health products and food: manufacturers can no longer claim the inflated benefits once seen on packaging.
There are more than lies though. Illiterate slogans like "It just got better!" tell you absolutely nothing while appearing to do so, because they do offer the comparison - besides such sloppy English reduces my confidence in the advertiser hence seller.
Without going to that link, because I don't follow links from anyone I don't know, it's just a matter of understanding what advertizer lingo means. When you read or hear "there's nothing better," it means that it's equal to the competition. Competitors can make the same claim and not be liars. That's just one of many examples. It's how they trick us into thinking what they want us to think. But you also need to be aware of outright lies such as enlargement pills and devices for a man's you-know-what. That part of a man won't get any bigger than it gets on it's own. Also, to say "doctors recommend" means that two or more doctors were likely paid to say that. Who's to say what field of expertise the doctors hold a PhD in? Philosophy? Entomology? Geology? We assume that they meant medical doctors but they didn't say that, specifically. We need to read between the lines or else we'll be fooled most of the time.
WTF thats crazy!!
people being generalized as numbers and demographics happend