Stephen Hawking played a special role.
The physicist was the only person to play himself in the series. After a meeting for a Star Trek video premiere, Leonard Nimoy, who played Spock in the original series, learned that Hawking was interested in appearing in the show. The actor arranged for the famous physicist to appear on Star Trek: Next Generation in 1993.
Of course, this hand gesture means "read between the lines"...
He came up with it for the character. He's the reason it's in the show. That's all that anyone needs to know. Pointy ears weren't a new thing, either.