Tolga, I am not exactly a Bf-109K-4 expert, but I do know that a lot of Bf-109K-4s had their outer main gear doors removed and their tailwheels set in a fixed position. If the tailwheels were in a fixed position, I can see no reason as to why the tailwheel doors would be in an open position.
According to the book "German Aircraft Landing Gear (A Detailed Study of German World War II Combat Aircraft)" by Gunther Sengfelder, the tailwheel doors of the Bf-109K-4 would only open upon retraction/extension of the tailwheel and, once in position (either extended or retracted) springs would close the tailwheel doors shut. So I think the closed position would be the most accurate.
By the way, thank you ever so much for asking this question. When I purchased this book my wife asked me why I would spend $35.00 on a textbook about landing gear. I said, "You never know, it might come in handy some day". And so it has.
Truth of the matter is, I bought this book because I found it to be so ridiculous that it was unique. I just had to have it.
