The new background is called "Altai" and follows the KDE trend for polygonal images.
The wallpaper is rich in blue, with yellow shades representing sunlight at the edge of a lake, which represents the mountain system "Altai" in Asia, which is south of Siberia.
KDE Plasma 5.22 will be officially released in June 2021. KDE Plasma 5.22 brings new features and updates, such as panel transparency, various applet changes, Wayland updates and more.
KDE Plasma 5.22
Feature Freeze: April 29, 2021
Beta: May 13, 2021.
Final release: June 8, 2021