Well…if you place a texture with a black disk (simulating a hole) which is on the right side on the front face, then Sketchup will make it appear on the left side on the reverse face.
So somehow, if you could see the front and the back face at the same time, you see the two black disk exactly in the same location, simulating a kind of hole.
This is also the case if you apply a transparent texture simulating a fence, or a brick texture, which would give you the impression that, on the back face, you see the back of the bricks as they are laid out on the front face.
Now, I agree. If the texture includes readable text, this does not really work for reading…
…but it seems to be natural that on the back face you the see the back of what you see on the front face (even if you did not put it yet on the front face!).