The pattern of corruption looks like a pixel format mixup or colour channel overflow. So I would bet it's related to the 10-bit/8-bit colour changes in Mesa and Mutter...
I can't reproduce it on my desktop (Haswell, 10-bit monitor). I can reproduce it on two laptops (Kaby Lake, 8-bit panels). Is the problem Ubuntu-specific? I've been wondering if our mesa patch(es) in this area are still necessary (since mutter fixed their side, didn't they?). ** Also affects: xorg-server (Ubuntu) Importance: Undecided Status: New ** Changed in: xorg-server (Ubuntu) Status: New => Confirmed ** Tags added: visual-quality ** Changed in: gnome-shell (Ubuntu) Importance: Undecided => Medium ** Changed in: mesa (Ubuntu) Importance: Undecided => Medium ** Changed in: mesa (Ubuntu) Status: Incomplete => Confirmed ** Changed in: mutter (Ubuntu) Importance: Undecided => Medium ** Changed in: xorg-server (Ubuntu) Importance: Undecided => Medium -- You received this bug notification because you are a member of Ubuntu-X, which is subscribed to mesa in Ubuntu. https://bugs.launchpad.net/bugs/1753776 Title: Graphics corruption (or distortion?) in login animation to Xorg sessions To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/gnome-shell/+bug/1753776/+subscriptions _______________________________________________ Mailing list: https://launchpad.net/~ubuntu-x-swat Post to : ubuntu-x-swat@lists.launchpad.net Unsubscribe : https://launchpad.net/~ubuntu-x-swat More help : https://help.launchpad.net/ListHelp