What does high-res mean? I downloaded Hokusai's 'Great Wave' and I got a 6.2MP JPG (3k pixels horizon.). That's not high-res at all when considering the origina

What does high-res mean? I downloaded Hokusai's 'Great Wave' and I got a 6.2MP JPG (3k pixels horizon.). That's not high-res at all when considering the original's size. Am I missing something?