thank you!, lets consider the classic example
https://upload.wikimedia.org/wikipedia/commons/thumb/8/8e/Time-dilation-002-mod.svg/660px-Time-dilation-002-mod.svg.png
assume that the distance between 2 mirror (L) is 300,000 kms, and at time = 0, the light packet start its journey, as per the diagram, after 2 seconds, the light should reach center of mirror A, by traveling 2 times D instead of L.
But,what if, the light is following the same straight vertical path for the stationary and moving observer, it should reach at a point in space where it is originated. ie, the location of mirror A when time = 0 , (the mirrors may have been moved - to the direction of its motion)
