Windows 11 introduced the Fluent Design System—rounded corners, translucent "Mica" materials, and depth. A Windows 13 Simulator typically ramps this up to 11 (or 13). Expect fully transparent glass effects, floating widgets that detach from the desktop, and a heavy reliance on blurring effects (Acrylic).
Many simulators experiment with removing the traditional Start Menu entirely. Some concepts replace it with a command-prompt-style interface or a "Command Center" that covers the whole screen, similar to the Windows 8 Metro interface but refined and more functional. windows 13 simulator