By the look of it, it seems the Pilot of the 2nd Aircraft just wants to avoid his Engines getting debris/dirt into them, from the Exhaust of the 1st Aircraft.
Its difficult to tell how close they are from the view in the Picture,so this seems to be the only conclusion I think.Maybe a side view would make things clearer.
Probably it would be better to mantain a greater seperation.
I may not win often, but I damn well never lose!!!