According to Prosser, it seems that one of the features of the power bank is the ability to reverse charge. This means that in theory, it will not only be able to charge your iPhone, but will also be able to charge something else placed on top of it, like another iPhone or more likely than not, the AirPods.
However, Prosser does note that there will be two versions of this MagSafe power bank. One version is expected to be a regular power bank that just charges the iPhone, but there will be another “premium” version that will come with reverse charging. He mentions that according to his source, they are unsure if Apple will release both versions or if only one will be launched.
What’s interesting is that a couple of weeks ago, it was reported that reverse wireless charging was a feature that would not debut in the iPhone anytime soon. This MagSafe rumor still kind of makes it true, but it could be that Apple is looking to introduce the feature but in a different way.