I suspect the "window manager" here is ignoring the resize hint, so it's squashing all the controls in a window that's too small to fit. Some tiling WMs don't cope well with said resize hints.
Perhaps try reproducing with a more mainstream WM (metacity in gnome, kwin in kde, xfce's default should also work) and see if it's still squished with the same theme.
Perhaps try reproducing with a more mainstream WM (metacity in gnome, kwin in kde, xfce's default should also work) and see if it's still squished with the same theme.