Latest version, Windows 10.
They are fine here, (2 different computers, one CCleaner Pro one CCleaner Free).
It looks like yours is trying to display 2 different icons side by side and of course the column is only meant for one icon so you are seeing half of each.
eg. half of the the Thunderbird icon and half of the Internet icon; half of the Chrome icon and half of the Applications icon.
I'm not sure what the one with Firefox is?
That's an odd one. What do the Internet and Applications icons look like in your CCleaner?
Is the Windows Tab also showing double icons or is it just the Applications tab?
To rule out it being a Windows glitch I'd do a 'Restart' (not Shutdown) of Windows to see if your Windows icon cache needs a refresh.
If a Restart doesn't fix it then you can delete the icon cache files and Windows will then rebuild them:
https://www.makeuseof.com/windows-rebuild-icon-cache/
Let us know if that doesn't put it right.