Let's take a look at what oversampling looks like: Click and drag the texture to rotate the plane.

Notice how details in the texture, in particular the motar between the bricks, tend to pop (disappear and reappear). This popping is most noticable around details (parts of the texture with a high-spatial frequency). This is indicative of aliasing (high-frequency details showing up in areas wher we expect to see low frequencies).