The best developers always find a way to subtly sign off on their own work without being too overt about it, and if you look closely at some of the spinning weather-mains/weathercocks of the various cities, you'll notice a very poignant similarity between that and the developer's logo. It's a pretty neat way of inserting yourself into your game, and symbolically means the development team are forever watching over what their millions of Witchers are getting up to from above.
