Some theme-provided app icons are blurred / low resolution in Installed apps

When you compare Applications/Installed and Home/Applications icons, you can see that the ones in Applications scope are blurred/low resolution, while the ones in Home are crisp. Other icons in Applications are high quality as well, only those theme-based are wrong.

It suggests that it's the image://theme/ provider is doing something wrong - we need to investigate which images are selected from the theme, since we're shipping 4 icons in total:

$ dpkg -S webbrowser-app.{svg,png}
ubuntu-mobile-icons: /usr/share/icons/ubuntu-mobile/apps/scalable/webbrowser-app.svg
webbrowser-app: /usr/share/icons/hicolor/scalable/apps/webbrowser-app.svg
ubuntu-mobile-icons: /usr/share/icons/ubuntu-mobile/apps/240/webbrowser-app.png
ubuntu-mobile-icons: /usr/share/icons/ubuntu-mobile/apps/144/webbrowser-app.png