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

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