The core principle is that a user should be able to understand the application's state from any screenshot. This focus on every frame builds user trust by demonstrating the quality of the application. Users judge an app's quality solely through its user interface, as they cannot see the code. A polished UI suggests developers have invested time in refining both the interface and the underlying code. In practice, this means avoiding undesirable visual glitches. These include white flashes between screens, partially loaded content, and content relayouting during loading. The UI must also be internally consistent in its messaging and status indicators. Precise animations are crucial, as they are often overlooked during development. A UI might look good in its static states but be janky during transitions. The idea of "every frame perfect" promotes UI craftsmanship. This discipline, even if not consciously noticed by users, translates to a better overall experience. Cutting corners on interstitial states can lead to corner-cutting in other areas of development.