De-shielding that board shows us some of the fun that's running the light show up top:

Texas Instruments TLC5971 LED driver

Cypress CY8C4245LQI-483 Programmable System-on-Chip, likely tasked with touch control

ON Semiconductor FPF1039 slew-rate-controlled load switch

Texas Instruments TPS62135 4 A step-down converter

The flip side of the board houses the LEDs and the diffuser that gives the indicator its cloudy look.

The plus and minus symbols are cut straight through the board, and each has its own little triad of LEDs plus a light guide to aim the photons where they're needed most.

The top side of the board (second photo) sports a neatly organized pattern of tiny divots—possibly a capacitive grid, like on the Google Home, for registering your taps and touches on the surface above.