“Meta submitted a specially crafted, non-public variant of its Llama 4 AI model to an online benchmark that may have unfairly boosted its leaderboard position over rivals.”
Meta ranked a custom chat version of Llama 4 on LMArena and released a different model to developers. The arena version gave long answers full of emojis. Meta did not deny it and said it experiments with custom variants. The leaderboard rewarded charm, and Meta tuned for charm.