Bug or New feature. Better Sky

Hi in this stage Mac edition - offline mode - Single player - elephant - expert - normal race - shifting sands i saw the sky with this lines. I don't know this happened because we want. If no i think this is a bug because the sky isn't normal and beautiful and must fix it. if we programmed in this way because it is more convenient then we should improve it. This image reduces the quality of the game because the game looks amateur and this is not true.