So the issue on my desktop (I installed regular Ubuntu, then Mate on top of it, because I’m just trying Mate right now, I will do a clean install later, if I finally decided to switch from Unity to Mate, but anyway it may causes the issue I dunno) so is when I move my mouse across Chromium’s icon, while it increases then decreases its size, it switches to the older Chromium icon, then back to normal. Only Chromium affected as I noticed so far.
So it’s must be an icon handling issue, or I don’t know, but still interesting and worth to mention in my opinion.
Another weird example: In Caja, some icons are extremely huge (.key file’s icon for example) oe to be more precise, they have the smallest and biggest version of their icons, but nothing between the two.