Source of the meeting participant mac_addr field

I am using the list meeting participants API https://api.zoom.us/v2/metrics/meetings/{meetingId}/participants.
The MAC address of the participants is provided.

Which MAC address is this? Is it supposed to match the address of the network interface that is being used for the call? Or is it for any interface on the participants device?
When I join a meeting using the Windows Zoom client, the reported mac_addr doesn’t appear to match any of the connected network interfaces.
Based on the vendor it may refer to a Microsoft Hyper-V network adapter, but doesn’t match any shown by “ipconfig /all”.