My 6yr Bryant/Carrier has a little > that points to either heat or cool if on.

If it has been manually put in emergency heat mode it displays "emerg" at the very bottom.

If it has automatically turned on the strips to "catch up" it indicates "aux heat" at the very bottom.

If it is in defrost mode no indicator shows up.

You can press the up and down arrows at the same time and get the outside temp and humidity level inside but this was an option and requires a temp sensor on the exterior unit.