What is a GUI On a Camera?
GUI stands for Graphical User Interface – pronounced GOO-ey. When relating to cameras, the GUI is the on-screen menu system. Essentially it’s the graphical way of showing the camera settings. Menus, tabs, sub-menus etc. It could also mean the way the camera settings are displayed on the screen during live view shooting.
If someone said “Wow, the GUI on Sony cameras is a mess” they mean the user interface (menus) are hard to understand.