I discovered after one year that by long pressing the car locking button on the remote I can close the car windows as well.

I had no idea about it and not being enough curious I didn’t find it out myself. It was only after a casual chat with a friend that it revealed.

The affordance of this feature is poor. There was no translation of what I know about interacting with buttons on a digital product and that physical user interface.

What can a designer do to make interfaces more discoverable? How can we make explicit the multiple functions a single button might have?