I've come across this UI issue many times designing e-commerce websites: you want to provide a graphic illustration for a category, let's say "Shirts." You select an image of one particular shirt as your graphic. And then when you put that design in front of users they assume that they can buy that very shirt. Obviously you recommend to your client that the corresponding grid page (some call it a family or category page) will have that very shirt available, perhaps merchandised first, but definitely above the fold. If not, your users will quickly become frustrated that they can't locate the product they clicked on.
My friend Micheal Summers at TrueAction referred to this as an issue of "-ness," and I love the term, partially because it sounds rather unintelligible the first time you hear it. On e-commerce sites we are often trying to illustrate categories like "shirt-ness" -- and it can get quite tricky.
For example, the Shirt graphic can become a maintenance nightmare very quickly. It means that for a whole season we need to have this same shirt in the grid, which doesn't make for very flexible merchandising. The Shirt graphic may need to be changed out seasonally -- will that confuse the user if their icon for shirt-ness keeps changing? Should we use an image of the best-selling shirt? What if this shirt style doesn't reflect the wide array of styles in the grid? Etc..
The screenshot above shows a brand trying to do something even trickier -- conveying brand-ness. Users expectation on an e-commerce site is to view product by category, so when confronted with these images their initial reaction is to read product-ness (dresses, jackets) into the them. In this particular case the challenge of communicating "-ness" will have to be addressed throughout the shopping experience.
Ever since I heard the term I see it all around me. A company logo, iconography on city streets, quick visual symbols are basically all attempting to communicate, at a glance, "-ness."