User blog comment:Xilinoc/Ch. 545 - Blue Stripes/@comment-4822693-20130709222211

I think that the "measurements", like someone else said are connected to Shunsui's cloak. My theory is that the all of them are going to go to see the Soul King after this. I'm guessing that the Soul King has an effect on near by souls similar to hokyoku Aizen. In other words unprotected souls will get destroyed. The robes are a sort of safety device. If this is the case then it means that Shunsui has been to the Royal Realm before, which would explain why he seems to know more about the Royal Guard than most people.

I think that Shunsui came to talk to Ichigo's friends, because he knows that Ichigo will reach the peak of his power during this arc. A Ichigo stronger than dangai Ichigo doesn't belong in the real world, he's too powerful. I'm not sure that the SS would let him run around anymore without restrictions on his power.