If you have a CAS that plots vector fields (the command is fieldplot in Maple and PlotVectorField or VectorPlot in Mathematica), use it to plot
$$
\mathbf{F}(x, y)=\left(y^2-2 x y\right) \mathbf{i}+\left(3 x y-6 x^2\right) \mathbf{j}
$$
Explain the appearance by finding the set of points $(x, y)$ such that $\mathbf{F}(x, y)=\mathbf{0}$.