it's an iconic shot & the sky gives it impact.
It's such a shame that there are so many cars in the shot because the power of the image is diminished by the fact that it is in effect another tourist destination.
BTW, I have the same shot as this from my visit a few years ago, though I shot it in B&W film.
I saw some of your other Auschwitz shots on Flickr, this is the standout for me. (do you have any more anywhere?)
If you're interested, I scanned my photos & put them online in 2001 -
http://www.neesam.com/auschwitz/