This is going to be ironically inconsistent with my previous post, in which I said I’m no big fan of naming things. But this one I did look up, because it was such an uncommon sight (actually someone else looked it up, but that’s between you and me). It’s Freyer’s purple emperor, peacefully sipping some muddy water.
The magical thing about this butterfly is that its wings change colour when you look at it from a different angle. So when it flies around it changes from orange-brown to an iridescent purple and back again. In this photo you can already see a bit of the iridescence on its far wings.
It also has a Latin name: Apatura metis.