If light passes through two slits and it reflects off a object that photon leaves some of itself behind and continues on as if you put paint on your hand and slap a wall then run, how many walls you slap depends on how much paint you got, when light reflects off the object or the slit where does it go is it passing through itself or is it colliding with itself in that direction and handing itself some extra light to continue like say you been running with paint on your hand and you have a train of people that follow you and you are the leader. What if you grab just a finger swap of paint for that extra inch foot mile etc. so when the rays reflects off the rectangle will that rectangle of photons continue colliding into each other and handing itself more photons or snatching some to create a another rectangle and so on till it fades away.