Update: We suspect that the three stones that make up SU 6173 may actually have been part of floor surface SU 6161 and fell into a possible cut in SU 6178. However, the suspected cut is not visible due to the presence of SU 6178, which may be covering the suspected cut's limits.
SU 6173 was used to level SU 6161.
Room G-1 center-west
SU 6137. Photo taken from the west.