The LCD + potentiometer would replace the three buttons in my example (Start, Stop, Play).
Buttons hold shirts closed. Switches can be open or closed, and can communicate information to the Arduino.
An LCD is used to display information. A potentiometer is used, with an Arduino, as a voltage divider device. The center tap will, therefore have varying voltage levels, depending on where the shaft is positioned. The varying voltage can be read by the Arduino, and the changing level can be used for controlling PWM outputs, for instance.
How do you intend to use an LCD and potentiometer to keep your shirt closed? Or did you mean switches? In which case, how will an LCD and potentiometer substitute for 3 switches?