The main body of Mossa's public and private art work was created with water colours and strong ink lines, the subjects including caricatures, Carnival or medieval scenes, portraits and landscapes, with a fascination for the French Riveria in particular.

Both father and son are still celebrated for raising the Carnival's prestige, and the event continues to be a major, large scale tourism attraction in Nice.

[8] Mossa's decade long Symbolist period (1900–1911) was his most prolific and began as a reaction to the recent boom of socialite leisure activity on the French Rivera,[9] his works comically satirising or condemning what was viewed as an increasingly materialistic society[10] and the perceived danger of the emerging New Woman at the turn of the century, whom Mossa appears to consider perverse by nature.

[16] Following the play's success, Mossa established the Lou Teatre de Barba Martin group, who performed his comedies 'Phygaço' (1924), 'La Tina' (1926) and 'Lou Rei Carneval' (1935), until 1940.

[2] From the end of the Second World War, Mossa devoted himself to creating works about the City of Nice, illustrating official documents, drawing armorial bearings and traditional suits of the County, and producing several watercolours of the region's landscapes.