The Apple HomePod mini product page reads that the built-in U1 chip, which Apple refers to as an "Ultra Wideband" chip for device approximation calculation, will be activated this winter.
Finally, a HomePod update that makes something fun
And now we know with which HomePod update: 14.4. The news broke after iOS 14.4 was released to developers in the very first beta update that was released yesterday.
There is no semi-open beta program for this HomePod update; instead, Apple has hand-picked its favorite testers, so we now know how it all works.
Note that the HomePod, ie big brother, does not have a U1 chip. iPhone has from the 11 series. Now the chip does not do much more than making AirDrop sharing a little more elegant with the ability to point to the device that will receive information.
This happens when approaching a HomePod mini with iOS 14.4 beta 1
Ok, so this is the thing: when the iPhone is near a mini, the phone starts to vibrate and the light becomes stronger on the small screen at the top (about 3.5 meters), a vibration rate that increases as you approach the speaker and until the two exchange the necessary information to play the desired music.
Then the interface shows this when the exchange from iPhone to HomePod mini is complete and the music is played: