Option available under Clock bubble settings:

Also in the phone app:

Prerequisites:

• Use Bubble Cloud as your watch face (seconds hand does not show in app drawer mode)
• Analog clock bubble
• Enable seconds hand
• Watch has to have a speaker – most newer ones don’t 🙁

Custom theme

Theme shown in the video is a custom theme put together from custom graphical components. For more info (and the downloadable components) see this post Creating your custom watch face