Currently the new horizontal workspace switcher only shows a series of
buttons, with no indication of the workspaces' contents. Go full GNOME 2
and add tiny draggable preview rectangles that represent the windows
on a particular workspace.
https://gitlab.gnome.org/GNOME/gnome-shell-extensions/merge_requests/74
Unlike in GNOME 2, the workspace indicator we display in the window list
isn't a workspace switcher, but a menu button that allows switching
workspaces via its menu. The reason for that is that a horizontal
in-place switcher would be at odds with the vertical workspace layout
used in GNOME 3.
However that reasoning doesn't apply when the layout is changed to a
horizontal one, so replace the button with a traditional workspace
switcher in that case.
https://gitlab.gnome.org/GNOME/gnome-shell-extensions/merge_requests/70