[masom]

Yes, there's a more complicated explanation as it's all happening as part of Bonjour https://developer.apple.com/bonjour/

The sender device broadcasts their identity, while the receiving devices will follow the Airdrop settings. When in contacts only and/or disabled, your device will not broadcast your personal identity in the clear.

Your device itself broadcasts its presence through various protocols.

This is a follow-up to the NetBIOS protocol that did the same (Windows shares is another example).