A couple chapters ago I decided I would use rounded corners as comic symbolism to denote flashbacks… and then forgot about it when I got to Carl’s Hiawatha story. So that’s why the first couple pages have straight-edged corners, and the rounded ones don’t begin until here. I’ll put it all right for the eventual printed volume, but here online is where I preserve all my original mistakes!
Many thanks to acrisp for posting the answer first to my mystery from last week, to Brad for (independently) posting it second, and to everyone else who went looking. I really appreciated it!