system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5:why is the Mona Lisa so highly coveted- I've seen so many other paintings that look technically a lot harder?
gpt
Five reasons:

1. The smile. It was the first painting of its kind to have someone smiling in such a way, so it was sort of a new era.

2. The brush strokes. He used strokes so small, they were damn near invisible, creating a very 'photographic' painting in a time when that wasn't really done.

3. Street Cred. Leonardo Da Vinci was an extremely talented guy, the quintessential renaissance man. He was a genius, and is thus rightly given praise.

4. Time. This painting took four years of Leonardo's life to make. 

5. Subject. Nobody's entirely sure who he's portraying, which is pretty weird for portraits. Usually, portraits like this one are commissioned by the person depicted, but it doesn't appear this was for anyone but Leonardo. Is it a girly version of him? A prostitute? A secret lover? Or just something out of his head?