The most important function of the Product Owner is to create a shared understanding for the product team, by understanding the customer, the customer experience, the business requirements, the technical limitations, and progress, pivots, and priorities.
“Someone will jump on a software quality issue that Apple has and I’ll be like, 'I can point out 20 bugs in our own shit right now. We know how hard this is. This is a hard thing to do. Imagine being Apple, when you have a billion people using your stuff. This is hard. It’s not that they don’t care. It’s not that they’re not paying attention. It’s just hard. We should know that ourselves.'”
Not design for mobile, not design for wearables and not UIs for IoT, but rather a holistic tool-set for designing products that are to be used by humans — a reminder of what design is and what it takes to design products for each of us.