Player 2 is a concept from local multiplayer gaming, where the first player starts a game and a second player joins with a separate controller. Online, this short joining cue has become shorthand for that moment, used in streams, edits and memes whenever another person drops in. It works because the idea is instantly understood even without showing a game screen. Creators reuse it for siblings, friends and pets entering a scene, turning an ordinary arrival into a joke about a new player spawning into the action.