Attempt to deiconify (unminimize) this.
On X11 the window manager may choose to ignore the request to deiconify. When using GTK+, use deiconify instead of the Window variant. Or better yet, you probably want to use present_with_time, which raises the window, focuses it, unminimizes it, and puts it on the current desktop.
| this |
a toplevel Window |