Apparently similarly mechanically powered displays involving cams to actuate number segments were pretty popular back in the day. Here's a YouTube video I came across one day a while back about one: https://youtu.be/TANe2d0VTGQ?si=unBJmfzs6A_7PWkM
I got irrationally angry that the first digit in the clock could only be 1 or nothing until I saw the actual mechanism and realized that they did that to probably save on material.