The brown jacket sits over a similarly coloured waistcoat and a light crew-neck top. Pale trousers create a clear break below the darker upper layers. Light shoes continue the lower part of the outfit. The wearer is shown in a posed step with the jacket open, so the photograph gives a view of the waistcoat's front. It does not show the back of the waistcoat, the fit while seated or the way the outfit would look with the jacket fastened.
If you want this kind of separation, try the waistcoat and trousers together before adding the jacket. Sit and stand, then check where the waistcoat meets the waistband. Add the jacket and compare the visible central area. If you expect to remove it during an event, look at the outfit without it as well. Record the colour break and inner neckline as separate preferences. Ask the host about any stated dress code; the photographed combination alone cannot determine whether it suits your invitation.