I took this photo last week. It was daylight when I took my break at work (on the day shift). The glancing illumination on the craggy cinderblock wall showed every grain that poked out. Some grains gathered together to protrude en masse from the planar surface and some gathered to sink below this plane to form a valley.
The photograph below contains two images of the same cinder block. The left and right halves are 180 degree flips of each other.
The block on the left contains a center island that appears to be in a depression; the same island on the right block appears to be on a high plateau.
So which is the actual brick and which is the rotated one?