Comment 15 for bug 1448407

Ok, what is weird is that your screenshot looks like icons on 100% zoom on my laptop, but maybe it's due to the scaling. Here they look a bit too big with a set up in zooms.

The way icons works is that the code looks for matches in the different theme directory (the index.theme has an Inherit= key which lists other themes to use), so e.g the ubuntu-mono themes inherits from Humanity, GNOME, hicolor, so the code is looking in all of those. Also if the exact name is not found, it fallback to more generic ones ("application-vnd.oasis.opendocument.text.png/svg" is tried first, then it tries "application-vnd.oasis.opendocument" then "application-vnd.oasis", etc)

It's likely that some of the icons are lacking at specific sizes in the theme