I am a huge user of BBM Groups, be it for collaborating with the team on certain things to just plain social chatter with like-minded people. One thing that was quite frustrating was that if some shared a picture with the group, you don't really get notified. Unless, you open up the BBM app and specifically go into the picture section and see the Spark.
With OS 10.2 you now have the option to be notified when someone shares a picture with the group or comments on a picture. By default this is toggled on, however, if you didn't want to be notified you can turn this off.
That's it. You don't have to be bothered with picture alerts in the Hub. If, in the future you want to be notified of picture uploads just repeat the process and toggle it back on.