Quite often the GUI on an embedded device is driven by the software team while the off screen controls are designed by the mechanical or electronic designers. Sometimes this leads to a system were these two parts of the same device are not well integrated. I have seen cases were icons or names used on the GUI are not consistent with those used on the housing.
On the other hand some devices do a beautiful job of marrying the two types of input. On my Sony camera, there is a dial which allows the user to choose the mode. The dial contains small icons. When you turn the dial you get to see the full name and a description of the new mode. This vanishes after a few seconds, so the extra information does not clutter the image of the picture to be taken.
By also showing a rounded outline around the icons being selected, the on-screen image looks like an extension of the physical dial. In other words, rotating the off-screen dial also rotates a disk that is displayed on the GUI. While this is tricky to describe the brief video below makes the idea clear.
While many other cameras only repeat the icon on the GUI, Sony make this feature far better in two ways. One is that the extra text means that the user can learn the meaning of the icons without resorting to the user manual. The second aspect is the smooth integration of the on-screen and off-screen controls makes this device feel like a single user interface, rather than two distinct interfaces to two different parts of the device.