It's called super-stimuli. I was taught this in highschool biology? (age 16 or so, that's high school in the US right? I always mix it up)
First the example of the seagulls[0], but immediately after that, the teacher showed us a Betty Boop / Jessica Rabbit -like comic book character, clearly demonstrating that, no of course it's not just birds. One thing I remember, for some images (depending on posture, mainly) you actually needed to use a ruler and work out the proportions because at first glance there was nothing wrong with them.
And yes, the advertising industry has of course been abusing this behavioural exploit since ever, to the point that I'm pretty sure there's a couple of EU laws against the most egregious types (though partially covered under false advertising of course).
[0] which is about a red dot the parents have on their beaks, and the offspring would peck at it to get food. except they preferred what was (iirc) basically a large flat yellow wooden plank with a larger red dot on it. are you sure you have the story right? (could be a different experiment, though) also, while the baby birds would prefer the non-feeding wooden plank, I kind of doubt they carried on the experiment to starvation.