It's code, I think....that allows us to "decode" what is being noted. If you have the key (relay) ,you see the note, if you don't have the key,
you are blind to it , aka "event cannot be loaded or ....bla bla bla ...black screen". 😂😂😂😂
Discussion
But I can receive DMs without all this, this sounds like adding uncertainty to everything 😅
From my understanding, if a person is not in your web of trust, and do not share the same relays as yours, or own relays that can read your notes, other Nostr users won't be able to see your notes.