His approach combined technical precision with a keen eye for social observation. Sommer photographed the Greek theatre of Syracuse and the statues of the Villa Nazionale. He also recorded the people who occupied these spaces. His catalogue includes street scenes of pasta makers drying their wares on wooden racks and public writers assisting young women at outdoor tables. These images provide a factual record of nineteenth-century Neapolitan life, from the tarantella dancers to the horse-drawn trams of the Santa Lucia district.

Modern collectors value Sommer for his ability to balance classical composition with raw, everyday details. His prints offer a window into a world where ancient history and modern industry coexisted. The sepia tones and sharp details of his work bring a sense of historical weight to a room without feeling dated. Whether capturing a funeral procession of monks or the busy commerce of Via Roma, his photography remains a clear and direct observation of a vanished era.