Thomson was an accomplished photographer in many areas, including landscapes, portraiture, street photography, and architectural photography, and his legacy is one of outstanding quality and breadth of coverage. His photography from the Far East enlightened the Victorian audience of Britain about the land, people, and cultures of China and South-East Asia. His pioneering work documenting the social conditions of the street people of London established him as one of the pioneers of photojournalism, and his publishing activities mark him out as an innovator in combining photography with the printed word.