
Open-source developer and Phoronix reader Gianluca Masci wrote in to share his proof-of-concept work for allowing per-monitor wallpapers with the GNOME Shell. This brings the needed architectural changes for independent, per-monitor backgrounds within the GNOME Shell.
As part of this work is also a configuration tool for GNOME Shell in handling the per-monitor background selection.
The work hasn't yet reached the stage of an upstream merge request, but for now the PoC Code is hosted via this GitHub repository with all the details. This development is also noted as AI supported in its creation.