Contrary to pop culture , the nose art was done for "photo ops" to send back home .. Then it was removed, they did not fly missions with nose art ..
If you look a photographs of actual combat mission footage taken diring the war, you will see MANY examples of Nose Art on the bombers and fighters while on the actual missions. There are also photos of aircraft that were shot down and crashlanded in enemy territory with their Nose Art intact. I doubt that the Germans painted the Nose Art on for a 'Photo Op'...
Did a bike a few years ago with nose art on the tank and can't recall the site but do a google on WWII air plane nose art and some great sites come up.