This is one of those things that doesn't seem like it should matter, but it does. If the lens is mounted in the exact center of the body, the images come out looking unbalanced. To produce balanced images, you have to offset the lens. Even very expensive pro mirrorless bodies are offset; that is, if you look directly down the center of the lens, you'll notice there is more camera body sticking out on one side than the other.
This is called the chirality of the optical path and it is surprisingly difficult to predict analytically. Companies will typically design the optical path, prototype it, and mount it on a jig to precisely measure the chirality. From this, they design the body with the proper offset.
Chirality is more noticeable the smaller the sensor and the shorter the lens. So on smart phones, which put tiny sensors behind wide-angle lenses, they have to get the offset just right. This explains why the lenses are in slightly different places on the body every time Apple updates their cameras.