Minecraft wiki entry for Development_versions, associated text: "The true meaning of covfefe"
Reference to a cryptic tweet from Donald Trump
"An illusion! What are you hiding?"
"Something's not quite right..."
The top two are references to Suramar City guards in World of Warcraft, who say these lines when a player, having an illusion on themself, goes nearby
The splash about the illusion could also be a reference to the illusioner.