I saw this beautiful butterfly in the garden, but I wasn't able to find it in my books about insects and searching the internet didn't help. I sent the picture and question to  Danmarks NaturGuide and very quickly received an answer. It is an Aurora. I actually knew that one from the garden. It is the one with the two big yellow-orange spots, but no way had I imagined it would look like that in a "folded" version. Besides telling me which butterfly it was, I was also sent a link so I could read more about the Aurora:

What a lovely help to get.