Braden Kowitz, from Google Ventures:

I’ve observed that teams often like to walk through UI designs as they would a blueprint – showing where each element belongs on the plan. Each screen shows how the product might look in a different situation, but the screens are not connected in any way. The problem is that when designs are presented this way, you’re only building an understanding of how the product looks. You’re not focusing on how the product works, and you’re not simulating how customers interact with it. So when teams critique designs as blueprints, it severely limits their ability to reason through the interactivity of the product.

The best product designers practice story-centered design. They begin by crafting stories that show how customers interact with a product, and only after they’ve accomplished that do they design screens as a way to tell that story of interaction.