I started my mini posts a while ago, but it's just dawned on me that some may wonder why I call them mini posts. Yeah, considering that some of my mini posts aren't so mini. Well, for me, a mini post is an update on a family or a certain sim that happens outside of their normal update, but can't wait until their new play session to be shared.
For example (since it's the first one that comes to mind) Sunni's pregnancy. She got knocked up and I had to explain it, but by the time I got back to playing her family she would have delivered. So she got a mini update. Also, the majority of my weddings are mini updates since they are planned after, and sometimes before that family or sim is scheduled to play.
So in a nutshell, a mini update for me is anything I feel is important, that needs to be shared before a scheduled update!