Matrix and linear transformation

Identify the following matrices as reflections, shears, scalings,rotation or projections for the unit square.

When i graph this i get a stright line y=2x.

In addition solving for the mapped values (x' and y') in terms of the inputed values x and y i again get the equation y'=2x'

which implies that the mapped y values are a function of the mapped x values.But i still can't interpret this. It is not a reflection, and it is not a dilation so what type of matrix is this?