Witsen is associated with Amsterdam Impressionism, though his style is more sombre than his peers. He frequently painted city views under grey skies or in the snow. His etchings and paintings feature a stillness that borders on melancholy. He preferred the quiet moments of urban life, focusing on waiting carriages or deserted streets. His work in London, such as Victoria Embankment, Londen, captures the specific damp atmosphere of the city.

The appeal of Witsen's work for modern interiors lies in its restrained colour palette and architectural clarity. His compositions, such as Gezicht over een gracht te Amsterdam, provide a calm presence in a room. Collectors value his skill in rendering light through mist and shadow. His portraits, like Portret van een jonge, onbekende vrouw, offer psychological depth without being sentimental. These prints work well in spaces that require a sophisticated, quiet aesthetic.