Created attachment 138481 [details] Small icons SUMMARY STEPS TO REPRODUCE 1. Install the same distribution on different machines and update everything. 2. Take some project and copy it both machines. 3. Open it with KDevelop on the two machines. OBSERVED RESULT Look at the Projects tool. It will look randomly one way or the other. EXPECTED RESULT The look of it should be consistent. SOFTWARE/OS VERSIONS Linux/KDE Plasma: Fedora 34 with KDE KDE Plasma Version: 5.21.5 KDE Frameworks Version: 5.81.0 Qt Version: 5.15.2 ADDITIONAL INFORMATION There might be a setting that controls this, but I haven't been able to stumble upon it. This has also been alternating across versions of KDevelop on the same machine. It looks one way, I update to newer version, it flips to the other look. Later there is a new version and after the update it flips back. After upgrading to Fedora 34, it flipped on one machine. I checked the other, which I also upgraded and updated, and it didn't. The same seems to hold for the Documents tool. Ideally it should behave like the File System tool, where you can change the icons by holding control and rotating the scroll wheel.
Created attachment 138482 [details] Large icons
*** Bug 437198 has been marked as a duplicate of this bug. ***
I figured out that this is controlled by KDE settings. One can select icon sizes for classes of icons. Settings -> Appearance -> Icons -> Configure Icon Sizes.