This is an animated city scape splash screen based on City Pixels Loading by Smokey.
Copy the entire city-pixels-loading-anim folder into ~/.local/share/plasma/look-and-feel. After doing this, it should appear within the Splash Screen page of System Settings.
I wrote a C# application to generate the city skyline and generate loopable animation frames, which I then encoded with FFMPEG. This can be found here:
https://github.com/logiclrd/CityScape/
The rest was all image manipulation and writing markup.