I think this would be easier to explain using strips of paper. Start by placing the strips horizontally, drawing a vertical line across all of them with a red pen. Then, shift the strips to the right relative to each other to represent latency. Next, having fold a section of each strip onto itself to shorten them beforehand, unfold them to show an extended length representing delay. Finally, fold them back again to represent waiting for the remaining delay from the transmit track.