His work bridges the gap between the drama of the Baroque movement and the emerging restraint of Neoclassicism. De Cock often produced detailed sketches for complex structures, such as his Schets voor de trap van een preekstoel or his Ontwerp voor een preekstoel. These drawings show his ability to translate three-dimensional space onto paper. His mythological subjects, including Apollo en Daphne and Venus en Amor, demonstrate a preference for clear lines and balanced compositions. He frequently designed garden ornaments, such as the Tuinvaas met deksel, which brought classical motifs into domestic outdoor spaces.

Modern collectors value de Cock for the architectural clarity of his compositions. His drawings and prints offer a glimpse into the planning stages of grand monuments. The monochromatic nature of his sketches makes them suitable for contemporary interiors that require a sense of history without overwhelming a room with colour. His work represents a transition toward the classical order that remains a staple of interior design. These prints provide a connection to the formal gardens and stately homes of the Southern Netherlands.