I don’t know the specifics but my guess is that the team responsible for search front end has people who are responsible for Easter eggs. Someone, maybe from that team, would have filed a launch ticket for that specific feature, and quickly obtained approvals from privacy, legal, and product management people. Then some engineer and designer probably volunteered themselves to do the work, and did it. Generally launch approvals are fairly streamlined, and only get bogged down when the thing being launched has complex privacy, security, or legal considerations. In this case I’d imagine those issues are almost nonexistent so that’s why it could happen so quickly.