can anyone explain me?

This is due to motion parallax. When we move, the stationary things around us seem to be moving.This motion is relative to us and is at different rates depending on their distance from the observer. The far off object seems to be moving slowly because ,of its distance ,the rate change of motion is slower than the object nearer.It tends to go in the opposite direction because we observes it with respect to the nearer object which is moving faster. Hence the farther object seems to be lagging behind .Its an optical phenomenon.