the usual symbol for a "like" on nostr is 🤙 and that's the phone hand gesture, so it's more like "i'm listening in" than "i approve"
Discussion
nostr vibe: gotcha buddy, high five
fedi vibe: are you okay?
it's the symbol i get when i search for "phone" though, because that's what Unicode had intended it to mean, and until this moment, that's what i assumed it meant. Google tells me the shaka sign is popular but i've never seen it before.