Saw G-VAST the other day and noticed a dark line painted(?) above the fifth window from the front, right side. Its just visible in the following image, and none of the earlier ones.
The line appeared to be the width of the window, displaced slightly forward, so not perfectly above the window, and seemed dark green or black. I'd guess (from120 feet away) that the marking was the width of the window by 3 inches vertically.
Wondered if anyone had an explanation.......
Regards - musang