Update README to clarify 3D observation method

Clarify the description of the 3D observation method by explaining the shifting of a fixed-size 3D window through the field and its benefits.

Author: xcontcom

README.md

@@ -93,10 +93,13 @@ Live demos:
 
 The same 3D system, observed differently.
 
-Instead of slicing the volume, a fixed observation cube is translated through
-the periodically closed field.
-Three orthogonal faces are sampled coherently and combined
-into a single isometric cube view.
+Instead of slicing the volume at a fixed position, this version lets you
+shift a fixed-size 3D window through the field.
+Because the field wraps around at the edges, shifting in X, Y, or Z
+never runs out of space and simply reveals another part of the same structure.
+
+Three orthogonal faces of this window are shown together and combined
+into a small isometric sketch for easier spatial intuition.
 
 Nothing changes in the dynamics —
 only the **way results are inspected**.