An infinitely long, thin wire carries a uniform linear charge density \(\lambda\). A student constructs an imaginary closed cubic Gaussian surface of edge length \(L\) oriented such that the line charge passes symmetrically through the centers of two opposing square faces. Although the net electric flux through the cube is equal to \(\dfrac{\lambda L}{\varepsilon_0}\), this Gaussian surface cannot be directly used to calculate the electric field magnitude produced by the wire. Which of the following provides the best explanation for this limitation?