His technique merged the precise detail of the Northern Renaissance with the monumentality of Italian art. Mor avoided the idealised styles of his contemporaries in the Habsburg Netherlands. He focused instead on the physical reality of his subjects. His portraits of figures such as the Duke of Alba and Mary Tudor are noted for their psychological intensity. He often used neutral backgrounds to ensure the viewer concentrated on the sitter. The resulting images possess a formal dignity that defined the visual identity of the Habsburg court.

Modern collectors value Mor for his directness and technical mastery. His work lacks the cluttered symbolism found in many Renaissance paintings. Technical studies, such as X-radiographs of his portraits, reveal the careful planning behind his compositions. The focus remains on the human face and the textures of clothing or armour. These prints offer a window into the personalities of the sixteenth century. His ability to capture a specific individual makes these portraits feel contemporary.