Posting snippets of your story is a fun exercise. Here is why:
#1. It is sort of a reward for the work you put in. After all, if you didn't write anything, you wouldn't have any snippets to post.
#2. It's fun to see what gems you have created.
Some writing is ho-hum. I look over my own work and see boring sentences such as "She walked outside." Sometimes a boring sentence is necessary and fits very nicely into your paragraph, but it doesn't sound impressive in a snippets collection.
However, as you read through your story, you find some unique sentences that can stand alone. Then you put them in a snippets post and feel very proud of them. For me, sometimes it's a confidence booster. Hey, look, I do have some good pieces in here!
#3. They are a way to share what you are writing without spoiling the story.
Seriously, if you can guess my plot from the 6 snippets I posted last Friday, you are either a genius or you are cheating.
Sometimes, I pass up posting a gem-of-a-sentence because it IS a spoiler.
But, more often, I just have fun picking out sentences that make you wonder what is happening in that scene and, hopefully, make you want to read more.