It's pretty clear that the design of the egg carton isn't going to change the flavor of the omelette.
Except, of course, it does.
It does because people can't judge the eggs until they eat them, but they can judge the packaging in the store. And if they choose someone else's product, you never get a chance.
Not only that, but the placebo effect creates a self-fulfilling prophecy. We like what we liked. The customer would rather be proven right than proven wrong.
That's why it's so important to understand the worldview and biases of the person you seek to influence, to connect with, to delight. And why the semiotics and stories we produce matter so much more than we imagine.
It's not always fair or right or efficient that we need to worry about how we and our work will be judged. Until we come up with a better way to communicate what we've done, though, prepare to be judged in advance.