Bloom

img0 is the default wallpaper of Windows 11's light theme. It was created by Spanish design studio Six N. Five, which created several other wallpapers for themes found in the aforementioned, as well as various wallpapers for Surface models and other Microsoft products. It depicts what appears to resemble a piece of blue material folded to resemble a rose, over a light blue-grey background.

Variants
There is also a variant named img19, which serves as the default wallpaper for dark mode and features the same blue material albeit over a very dark blue background. This variant was in turn used as the basis of the default lock screen wallpaper, img100.

An animated version of this wallpaper also appears on Six N. Five's website, which has a section dedicated to this wallpaper. This version depicts the "flower" blooming. It also has the original versions of both the light and dark wallpapers, which feature more space, so it is likely Microsoft further cropped them to provide more focus on the main element of the wallpaper.

Credits
The corresponding section on Six N. Five's website credits the following people for creating this wallpaper, along with special thanks to the Microsoft Design Team:
 * Client: Microsoft
 * Creative Direction: Samuel Clarke, Cassie Klingler, Cristina Koehn.
 * Art Direction: Six N. Five.
 * 3D Artists: Valery Polehenky, Nil Estany, Joan Garcia Pons, Ezequiel Pini.