  The plane-mirror symmetry previously noticed in the Cosmic Microwave
Background (CMB) temperature anisotropy maps of Wilkinson Microwave Anisotropy
Probe is shown to possess certain anomalous properties. The degree of the
randomness determined by the Kolmogorov stochasticity parameter in the both
symmetry regions appears to have identical values which, however, essentially
differ from the corresponding values for other sky regions. If the mirroring
were of cosmological origin, this would imply either additional randomizing
properties in those directions of the Universe or their different line-of-sight
depth. This analysis also provides a way to test the hypothesis of a link
between the nature of dark energy and inhomogeneities.
