The hole is substantially bigger than the size of the house. This allows for construction of the foundation and basement walls, as well as the addition of drainage. Rather than the house having gutters, the lot is drained by below surface channels out to the street. This means the back of the house will be elevated relative to the ground.
The area under the master bedroom, toward the back of this picture is dug out but will not be part of the basement, hence the slight rise. The area under the garage, front left, will neither be dug out or part of the garage.