Looking at the laminated binder is not a nominal case, thankfully. Think of it as a cache miss.

Most checkout clerks have memorized the codes and don't refer to the binder anymore. Perhaps you saw a new employee.

Also, many fruits/veggies have stickers on them with the code (either numeric or bar-code) so you don't have to do a lookup into "the binder". That's how you can easily go through the "self checkout" lanes (although there is a fallback in the form of a "virtual binder" in the UI if you can't find the code and want to select your produce from a set of buttons/images on the screen, with optional string searches).

It's often key to have a differentiator in the form of a code because different items can be visually equivalent (think about bananas vs organic bananas).