If a transaction with the pixel art stays in the mempool for 336 hours it will be added in the leaderboard section. The rankings depend on the number of days spent in the mempool without being included in the blocks and chain length. No transaction in the mempool combined with its mempool ancestors can exceed 25 transactions or 101KvB in weight.
First free lunch pixel art: 6ae02bc54e9ae1ab153b6d713653f6ccd136589ca3858ccc7685be1802b83e94