Comment 2 for bug 875770

Here is why it doesn't happen in indicator-multiload:

    private void updategraphsview() {
        this.indicator.set_icon(this.iconwrite());
        // fix icon size if using the fallback GtkStatusIcon
        foreach (var toplevel in Gtk.Window.list_toplevels()) {
            if (toplevel.get_type().name() != "GtkTrayIcon" || !(toplevel is Gtk.Container))
                continue;
            ((Gtk.Container) toplevel).foreach((w) => {
                if (!(w is Gtk.Image))
                    return;
                ((Gtk.Image) w).pixel_size = (int) uint.max(this.lasticonwidth, this.height);
            });
        }
    }