Can Anyone tell what just happened...?

Hello all the people following my tutorial. I am sharing some steps and i would like to know how many of you can really tell what just happened.

Step 1 : I opened one of my post.

Step 2 : I see the rewards on that post , it is 655 BP.

Step 3 : I came back again after a minute and it was 494 BP.

So can anyone guess and tell me what can be thing behind this.

Write down in comments below and the right answer will receive a good upvote from @blurtutorials.

Thank You