Is that legal?

[Torbiel]

Please have a look at this picture showing LOT's B767 captain in-flight over the Ocean.

http://www.airfoto.pl/index.php?sub=single&id=9151&pict=lr&empty=yes&clr=yes

In the discussion below the picture one person claims that the practice of covering cockpit window is illegal. Other claim it is done by all pilots around the world. So, is it legal or not?

I'd appreciate your opinions.