[SOLVED] Change in Desktop icon appearance - is this anything to worry about?

[m654321]

Every now and then the appearance of LibreOffice and/or other icons changes on my Desktop screen. The new appearance may last a while, sometimes only a short time, but the icons always seem to revert back to their normal appearance. This link shows what happens sometimes on one of my laptops: https://imgur.com/a/u8uly

If you look at these two screenshots, the first shows the normal appearance of 3 x LibreOffice icons and 1 x *.jpg file.
The second picture shows the appearance they sometimes acquire on rebooting.

Has anyone else observed this?  Is it anything to worry about?

[UltraCookie]

do you sometimes use lite tweaks to delete the thumbnail cache? because that's what that is. or your machine deletes them on its own for some reason.

[m654321]

do you sometimes use lite tweaks to delete the thumbnail cache? because that's what that is. or your machine deletes them on its own for some reason.

Yes, I do use thumbnail tweaks. So, that explains it then. Thanks UltraCookie, you're a star. I knew someone out there on the LL forum would know ...