As the name suggests, the origins of this shoe is found in Oxford University. Students wore a half boot called the Oxonion in the 1800s which was the forefather of this shoe. The oxford became a very formal shoe which could be attributed to the contoured unfussy design of a closed lacing system. (Compare this to the open design on a derby shoe). This black wine oxford brogue could be perceived as more formal due to the fact there is full brogue detail. However, the fact there is a deep plumb insert tones down this aspect and makes for a little more fun than a plain oxford brogue. This oxford brogue definitely has flashes of personality and could be worn casually as much as it could formally.
Check out this blog for various ways to wear this type of shoe.