Files still displayed in Opus after having them removed from the desktop in Windows Explorer

A friend wonders why Opus displays files in the desktop folder, despite they have being removed. In Windows Explorer however, those files seem to be gone. Are the files still being kept as real files or can they be deleted from Opus somehow?

Ps., it's a dispute. In my Opinion there are things going on with those virtual folders, which i avoid to use.

See Changes to folders are not being detected for how to diagnose it.