It could but I don't think it does. Has anyone built a gait recognition system? It would be tricky because it also varies simply depending on your shoes, if you're wearing a heavy backpack, if you're rolling a suitcase, etc.
It's also actually really easy to change your gait if you want. Just watch someone, and then copy how they walk. Start by paying attention to whether the hold their more fixed "center" of movement in their chest, abdomen, or waist (or where in between), then match their degree of stiffness or sway, and you're most of the way there. It's a pretty common acting exercise.
Must be orders of magnitude harder, since it needs video instead of just one photo.
That said, I'm sure it exists.
> Has anyone built a gait recognition system?
Years ago it was announced that some Chinese cities would use gait recognition for surveillance, but I don't know if the deployment stuck. I remember a video showing off the tech, although I can't look for it right now.
I searched google scholar for "gait surveillance" articles since 2023 and got 12,000 results. I'd be willing to bet some of them are in operation at this point.