Icecream is a good example - the potatoes get that cracked rough texture when scooped, which is what they want, real icecream would be a smooth ball usually. I have this from a friend who did said photography.

Think McDonalds burgers with someone anchoring each individual sesame seed with flour paste so they're spaced evenly, and plastic tubes in t he burger to provide that drop of "meat juice" (or catsup, sometimes) that rolls out of the burger when filmed.

I'd love to do a course on food photography.