These watch faces demonstrate functionality of the watch, and aren't generally watch faces you'd build into a working firmware.
This watch face displays all of the characters in the Sensor Watch character set. You can advance from one character to the next with a short press of the Alarm button.
This watch face may be useful to watch face developers, in that it can help them to understand which characters will work in different positions.
This watch was designed for the Crowd Supply marketing team, so they could photograph the various functions of Sensor Watch. The Alarm button advances through static screens that simulate different watch faces.
This watch face may only be useful to you if you need to photograph Sensor Watch, i.e. for a blog post.