Octree case study

Hello everyone!

I have a case study. I created an octree of the point cloud. Resolution was 2m. From the octree I retrieved information that:

24 leafs,
13 branches,
33 leaf nodes,
4 levels of depth (1..4),
1 of level 1 (root),
3 of level 2,
5 of level 3,
24 of level 4 (leaf),

were automatically created. I wonder how does it work. Octree should have 8 children and when I look at the data only 3 levels of depth would be enough. I also wonder why there is 13 branches and 3 elements of level 2. Here are some pictures: