Pickenoy painted large Schuttersstukken, group portraits of the regents of the orphanage, and individual portraits of local or national celebrities like Nicolaes Tulp, Cornelis de Graeff, Maarten Tromp and Jochem Swartenhont, Elisabeth Bas's husband.
The earliest picture ascribed to the artist is "Dr. Sebastiaen Egbertz de Vrij's Osteological Presentation" of 1619, now in Amsterdam Historisch Museum.
Around 1638 he bought the house next to Rembrandt van Rijn from Nicolaes Seys Pauw, on the corner of Sint Anthoniessluis and Jodenbreestraat, a fashionable area with many painters, art dealers, jewellers and so on.
In 1639 Rembrandt returned to the neighbourhood as he bought the house next to Pickenoys, on the site of the present day Rembrandthuis.
Typical of Pickenoy are the fiercely invading light that makes the heads stand out sharply, the somewhat exaggerated gestures, the large greenish brown shadows and the odd-shaped eyes.