As I understand , air conditioner is a heat exchanger. Works by removing heat from the air.

Not sure on the cool or dry function, me thinks you would need a heater operating to dry the air .

The cool would be normal operation without heater.

Got this from Google. ''The dry mode or dehumidification is a feature that can be found on several ducted and split-type air conditioning units that can reduce humidity levels in a room. It is intended for days when the weather is humid but not too hot or too cold''.
We use this setting on the home A/C unit and it works well. Cool room to how you want it then change setting to dehumidification.
the teardrop symbol. Keeps the room cool and is cheaper to run.