This scaling transformation is characterized by a three-dimensional vector. Its coordinates define how much scaling is done in each direction. If all three coordinates are equal, the scaling is uniform (isotropic) and the aspect ratio of the element is preserved (this is a homothetic transformation).
When a coordinate value is outside the [-1, 1] range, the element grows along that dimension; when inside, it shrinks. If it is negative, the result a point reflection in that dimension. A value of 1 has no effect.