1. A thermostat for controlling the operation of a heating, ventilation, and air conditioning (HVAC) system, the thermostat comprising: a housing; a user-interface component coupled to the housing and including a mechanically movable input component and an electronic display, and being configured to receive input from a user via a mechanical movement of the mechanically movable input component, the input being indicative of an adjustment of an HVAC-related setting; and a processor coupled to the user-interface component and configured to: receive a first input from the user via mechanical movement of the mechanically movable input component, the first input corresponding to a first adjustment of the HVAC-related setting; compare on a real-time basis the first adjustment of the HVAC-related setting against a circumstance under which feedback is to be presented to the user, the circumstance being indicative of responsible energy usage of the HVAC system controlled by the thermostat; determine, in real-time and based on the comparison, that the first adjustment of the HVAC-related setting corresponds to a responsible energy usage of the HVAC system; in response to said determination, cause a visual icon to be displayed to the user in real-time on the electronic display; receive a second input from the user via mechanical movement of the mechanically movable input component, the second input corresponding to a second adjustment of the HVAC-related setting; determine in real-time that the second adjustment of the HVAC-related setting corresponds to an increased degree of responsible energy usage of the HVAC system; and in response to said determination, cause the visual icon displayed on the electronic display to brighten to an intensity level corresponding to the increased degree of responsible energy usage of the HVAC system, the visual icon being brightened in real time as the second input is received via mechanical movement of the mechanically movable input component.