Apple's drawings show a MacBook with charging coils placed underneath the trackpad, as well as on each side of it, plus coils beneath the lid for charging other devices wirelessly when the MacBook is closed. There'd also be magnets in each device for correctly aligning them to the conductive coil of the other.
Apple explains that built-in reverse wireless charging can solve the problem of carrying around too many power adaptors when carrying multiple devices. It could be useful if and when people start traveling again after the COVID-19 coronavirus pandemic is over.
"Some electronic devices include one or more rechargeable batteries that may require external power to recharge," Apple notes.
"Often, these devices may be charged using a common or standardized electrical connector or cable. For example, some devices may be charged using a universal serial bus ("USB") connector or cable. However, despite having standardized connectors and cable, each device may require a separate or dedicated power supply to charge. In some cases, having separate power supplies for each device may be burdensome to use, store, and/or transport."