They do spread their wings in flight, but the few photos/vids I bothered to find it's still quite distinct from the classical pinned position (in terms of the angles fore/aft more than anything).

I'm sure it's a _possible_ position in which to find many species, but it seems like at best a rare one.

Part of it is that mostly I've seen, in person, butterflies in flight - they rarely alight on a plant close enough to inspect in detail and in flight they do appear to flap like a book opening and closing; one doesn't really see the pitch changes of the wing, it looks like a simple motion.

I've got some pictures of red admirals (it painted ladies, not sure) resting in "dead" pose on brambles somewhere that I took only because I'd seen this article.

> mostly I've seen, in person, butterflies in flight - they rarely alight on a plant close enough to inspect in detail and in flight they do appear to flap like a book opening and closing

My father grows milkweed to support a population of monarchs. They also flap their wings open and closed while resting.