When Apple introduced its new iPhone 12 series a couple of weeks ago, it showed off a new MagSafe charging feature. The feature magnetically holds a charger in the proper position for wireless charging, but apparently, this wasn't all the company had up its sleeve when it came to new wireless charging technologies.
According to some FCC filings, these devices could support reverse wireless charging at up to 5W, if Apple ever decided to activate it. Unfortunately, it's already limited, with one of the documents saying, "currently the only accessory that can be charged by iPhones is an external potential apple accessory in future".
Reverse wireless charging is not a new concept, as firms like Huawei and Samsung have been doing it for a while now. The idea isn't so much about charging a buddy's phone, but more about charging your own peripherals. For example, if you've got the wireless charging case for your AirPods, you'd be able to use your phone to charge that, or it might work with an Apple Watch as well.
As speculated by The Verge, it's possible that the reason that Apple didn't announce this at its launch event two weeks ago was because the accessory that this works with isn't announced yet. Perhaps that means that new AirPods are imminent.