Question when rendering two vti files in Paraview

Hello. I have a question.(First of all, please understand my lack of English)

When rendering two vtk files in paraview, I can recognize the relative position of the objects. As follows.


So I can recognize whether the white object is on the front or the back.

However, when two different vti files overlap, the relative position seems to be ambiguous. As follows.



In the direction of the arrow, B is the front.
But it still looks like A is at the beginning(Bottom picture). I want to know what is the reason for this.

I would really appreciate it if you let me know.