What is it?

Print it, put the labels on the little track, stick it to your four-function controller so you can remember what devices it's associated to in what modes.

Which Icons does it have?

A blank icon, plus Apple, Windows, Steam (Deck), and Nintendo Switch.

How do I stick it to a Controller?

The base is amply wide enough for 5mm VHB tape.

How Should I Print it?

I recommend PLA, for high dimensional accuracy, and to print multiple of all parts (they're very small and print quickly.) That way you can pick the ones with the most legible logos.