It's because Apple added an extra column of app icons. There are now six icons in a row instead of five. Revolutionary. That probably comes across as more sarcastic or cutting than poor tvOS deserves.

Windows makes it easy (although not obvious) to customize the Taskbar with custom icons. You don’t need a third-party app, just the icon files to replace the defaults. If you’re theming your ...

Click an ellipsis button on your taskbar, and a new icon overflow menu opens up, allowing you to interact with any of those extra icons the same way you would if they were sitting on the taskbar.