I take it the photo of yours may be dated early 1940, maybe during transit prior to operation Nordmark? Anyway, dating the different deck plating of the bridge aboard the Gneisenau is definitely not my cup of tea but I am however capable of making deductions. My instant thought goes to the continuous dillemma of these ships ... sea spray. They shipped a lot of water which I think could have made the outdoor bridge area a slippery place. So, to keep it reasonably dry they could have laid down an extra set of deck plating with draining holes on top of the original one in order to keep the shipped water below and away. Just a guess but it seems plausible. So on, if my deduction holds water then I figure installation could have been performed during the bow rebuild period, the winter of 1938-39. This would in turn mean that if the Gneisenau really recorded and attempted to remedy such a "flaw" it would probably be executed simultaneously aboard the Scharnhorst, maybe even before she entered commission.
However, this is far too spesific for me. I'm still reasonably sure the quiz picture of this thread is captured aboard the Gneisenau. You see, that photo is one of several photos I have covering the particular event as described above.