Oh! Something I took a part in on HN. That's a first. Almost everything there was practical. Highly recommend checking out all of Max's work, beaming with creativity.
So its not mentioned on the post but is this your actual passport photo that was accepted and used and you have it on your physical passport right now?
Don't know about Britain but the US also allows passport renewals by mail, so they can't check the photo against your face but they presumably can check it against your previous passport photo.