How to read off the set represented by a van-Emde-Boas tree?

Question

I'm reviewing my background in Algorithms and DS design. Specifically I never went through the van Emde Boas Tree. Though I can undestand the proto-vEB with related picture. I'm struggling to understand the actual data structure. I have no clue how the "min" and "max" members are actually used, I'm not talking about the procedures but just how the following picture is supposed to be interpreted. Can anyone help me with this?