I found the deepin-wallpapers package installed as a dependency at 99.62 MiB. I traced through the dependent packages, and it turns out it’s because of deepin-boot-maker. Here’s the dependency chain:
deepin-boot-maker > deepin-qt5integration > dtkwidget > dtkcore > deepin-desktop-base > deepin-wallpapers
Isn’t it strange that deepin-boot-maker would require deepin-wallpapers? Because I have a feeling that something in this chain of dependencies is unnecessary.