Infantin Maria Anna (1606-1646), Kaiserin, im Alter von 4 bis 5 Monaten, Bildnis in ganzer Figur

Painted in 1607, this portrait of the Infanta María Anna at four to five months of age is even more extreme than the nine-month portrait of her sister Anna painted five years earlier: a baby of barely five months is formally presented in full court costume against a dark ground, her very existence as a healthy Habsburg infant the painting's primary content. María Anna (1606–1646) would grow to become Empress and Queen of Hungary as the wife of Ferdinand III — but in 1607 she was an infant whose survival was not guaranteed, and whose healthy documented appearance served a diplomatic function. Pantoja was tasked with recording Habsburg dynastic production with the same professional thoroughness he brought to portraits of adult rulers. The Kunsthistorisches Museum holds this painting alongside the other infant portraits in the cycle, creating a remarkable record of the Spanish Habsburg nursery in the early seventeenth century.

At four to five months, the sitter's features are even less distinct than in infant portraits of older babies. Pantoja renders the face with gentle, undifferentiated modelling that captures newborn softness without detail. The costume dominates completely: its elaborate embroidery and stiffened silhouette are rendered with the same technical care Pantoja applied to adult royal dress, making the disparity between infant and garment the painting's central visual fact.