I think it's overblown. It made me pay more attention to butterflies in the real world and what I see is when landed they often flap their wings intermittently. So I just think of the drawings with wings open as catching one of those moments.

I took a look at some slow mo videos and midflight photos, and these were really interesting. In particular what seemed interesting is how in some videos they almost like swam through the air in which case they did extend their wings up front as if to grab air under it and then they brought them back down. So the animation on the web app is more static, but I don't think it's fair to call it a dead butterfly based on that. Also I think I now understand why there's a swimming technique called butterfly.

Seeing those slow mo videos and some of the images in the edamstra link I think it's a bit unfair to criticise some of the things like earrings etc, because with many of those it's very plausible they could be mid-flight moments (especially earrings as they are literally in the air).

And the "dead butterfly" shirt seems to be very aware and all of those could be same butterfly during its flight representing all the possible positions.

Out of curiousity I took a look at some midflight photos as well as slow mo videos. It could also vary by butterfly type, but there were definitely midflight photos were I saw wings quite extended front. Also in slow mo it almost looks as if they are swimming through air where they extend wings front to grab air and bring them back down. I suggest taking a look at some slow mo videos. It now occurs to me why there's a swimming technique called butterfly. The animation in the web app doesn't do the swimming technique justice, it's rather static, but at least I do think at certain point they have their wings quite extended, so unless you animate this whole thing, I don't think it's as fair to call it dead compared to if it's standing by with wings extended.