Throw a rock in New York City, and apparently you’ll hit an AI food ad.

At least that was X user Maggie Moda’s assessment after spotting a series of peculiar sidewalk signs outside the city’s delis and cafés in a post that has since racked up 2.8 million views. There were croissant sandwiches with almost comically perfect layers, an affogato with a side of random holes, and a chopped-cheese hero with cheese melted a little too perfectly over every piece of meat. 

Generative AI is giving restaurants a cheap and remarkably easy alternative to photographing the food they sell. For small businesses without the time or money for professional food photography, that can be a real advantage. But the backlash to AI food ads reveals a paradox: Some customers would rather see an imperfect picture of a meal that actually existed than a polished one that didn’t.

That distinction matters beyond whether AI food looks gross. Restaurants have been making food look better in advertisements for decades, but generative AI makes it possible to advertise a photorealistic meal that never existed at all. And because that imaginary meal is being used to sell a real product to real customers, it raises an old question in a new way. How different can the food in the ad be from the food on the plate before it becomes deceptive?

The closer you look at an AI ad, the less it resembles lunch and the more it starts to trigger trypophobia—the fear of a pattern of holes. Sandwiches contain identical holes and repeating ingredients. One viral burrito has so many tiny holes that the internet simply christened it the “trypophobia burrito.”

In other ads, cheese melts without an obvious beginning or end. Ingredients multiply into unnaturally neat rows. Croissants achieve levels of flakiness that seem to defy structural engineering. The images have become recognizable enough to earn their own unappetizing nickname: food slop. And not the sloppy Joe kind—AI slop.

The business case for AI slop

To restaurants, though, the appeal isn’t difficult to understand. Professional-looking food advertising no longer necessarily requires professional food photography.

When Grind & Unwind opened on San Francisco’s Haight Street in May, owners AJ and Lyndsey Lozano put a temporary menu in the window featuring AI-generated images of the restaurant’s food while they got the new business up and running, according to SFGATE. The internet was not impressed. A Reddit post titled “Yum, slop” drew more than 670 upvotes, with commenters comparing the focaccia to a “loofah” and a “lung.”

But the reason for the AI images was considerably less dramatic than the backlash. Lozano told SFGATE the pictures were only supposed to be temporary while the couple opened their first restaurant and cared for three children under 5.

A Chicago deli offered essentially the same explanation. Chi-Town Deli manager Ali Malik told Business Insider that its AI-generated sandwich images were temporary while the restaurant waited for a new sign featuring actual photographs.

Before AI slop, there were mashed potatoes 

For all the futuristic weirdness, fake food in advertising is remarkably old. In the 1965 Supreme Court case FTC v. Colgate-Palmolive Co., the justices even contemplated a familiar advertising trick: using mashed potatoes as a stand-in for ice cream.

The fake food itself wasn’t necessarily the problem. Rebecca Tushnet, a Harvard Law School professor who specializes in advertising and trademark law, told Fortune that advertisers can use images that aren’t real as long as they don’t mislead consumers about what they’re buying.

“If a reasonable consumer would understand that the image was making actual claims about the composition or quality of the food, then that could be deceptive,” she said. But if it’s simply showing the general kind of thing a customer will get, “then it is not likely to be deceptive.”

Generative AI makes that old distinction considerably stranger. Instead of mashed potatoes pretending to be ice cream, restaurants can now advertise food that never sat in front of a camera at all.

“The image itself can make a claim about the product’s size, quantity, ingredients, quality, or appearance, even if the ad never says those things in words,” Libby O’Neill, partner and deputy chair of advertising, marketing and promotions at Loeb & Loeb LLP, told Fortune.

And an “AI-generated” label isn’t necessarily a get-out-of-jail-free card. “It explains how the image was made; it does not correct a false impression about what is actually being sold,” she said.

Her rule of thumb is simpler: “Sell the product you depict, and depict the product you sell.”

This story was originally featured on Fortune.com