Pretty strange. Buildings of the size have to be anchored to bedrock. That said, I wonder if the earthquake proof features are allowing it to shift? Some buildings are designed to sway with counterweighting. Some buildings are actually sitting on ball bearings.
Ideally, but sometimes not. In theory, depending on the ground, deep enough pilings should provide enough restive force for the weight of the building. Effectively the foundation "floats". Apparently calculations were off on the ground around this building and this one is "sinking".