An Unannounced OpenAI Image Model, 'mona-lisa-1', Was Caught on LM Arena and Confirmed by Its Own SynthID Watermark

r/singularity (222 upvotes / 74 comments), AiBattle on X, corroborated by all-ai.de and IT168·medium signalXBlueskyLinkedInCopy link

A previously unknown image model codenamed mona-lisa-1 appeared on the LM Arena blind-test leaderboard with no announcement, drawing 222 upvotes on r/singularity. Attribution did not come from OpenAI — a user ran a mona-lisa-1 output through OpenAI's official verification service, which detected the SynthID signal OpenAI uses to mark its own content. Reactions are genuinely split: one tester called it "extremely better than Image 2," while others reported visible noise and texture errors. There are no official benchmarks, docs, pricing, or even confirmation whether this becomes GPT Image 3, a 2.5 update, or stays internal.