OpenAI's Anonymous Image Model Hits LMArena, Exposed by SynthID Watermark

新智元 · wechat · 2026-08-10

An anonymous image model codenamed 'mona-lisa-1' has quietly appeared on the LMArena blind test leaderboard. Developers used OpenAI's verification tool to discover a SynthID watermark, confirming it as OpenAI's new release.

Tests show that compared to the current GPTImage2, this model significantly improves in realism and detail, with noticeably less plastic feel. It easily handles complex infographics, web UIs, and even human organ breakdown diagrams. However, multiple tests indicate its knowledge base is stuck in 2025, suggesting it's not a new architecture but a new checkpoint on the same foundation.

Related event: Mysterious OpenAI Image Model 'Mona-lisa-1' Spotted on LMArena(4 posts)→

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