Why do Japanese people post random pictures on social media?

(Please excuse me, English isn't my mother tongue; I'm using Google Translate).

I've been wondering about this for a while now when I’m browsing X (or Twitter, lol).
To give you some context, I follow a lot of Japanese artists who are very skilled in art, and I’ve noticed a pattern. Many of them post really random photos (like a simple picture of the sky, pictures of seashells, buildings, mug, grass etc.. ). Often the pictures are not framed correctly, and the image quality isn't great. I also get the impression that many Japanese people are very passionate about photography, like it’s a common hobby.

Does anyone know why Japanese people have such a strong interest in taking pictures/ posting pictures on social media? Please why are they doing this?