When on, this node publishes a presence event (DID + npub only — never an onion) so other nodes can find you and request to peer. Inbound requests land in the panel below for your approval. Off by default.
Presence events are always signed with this node's dedicated discovery key. Your personal identities are never used for node discovery, so unlike the app sign-in overlay there is nothing to choose here.
Every presence event carries a Schnorr signature (NIP-01) made with the key above — relays reject unsigned events, so anything you see via discovery was cryptographically signed by its node. Your onion address is never part of this event; it is only shared over encrypted DMs (NIP-44) after you approve a peer.