The painting in center background on the floor, of a warrior in a red cap, is the only painting that occurs both in Jan Brueghel's evocations of the collection of the archdukes and in Guillam (aka Willem) van Haecht's recreation of the collection of Cornelis van der Geest, with the archdukes visiting. My hypothesis is that the painting was given as a gift by van der Geest to the archdukes, after he refused to sell them the Quentin Matsys Madonna they wanted. The painting of the soldier has never been identified.
This painting is part of a series of the five sense completed between 1617-1618. Please see:
Copy of whole series attributed to Jan the Younger, Ertz 1984 cat. #s 178-182; all panel, 68.5 x 112, all in American private collection.
A close copy on panel (70 x 112 cm), sold at auction by de Hirsch, June 17, 1904, #12.
A copy on panel (70 x 112 cm) attributed to Jan Brueghel and van Balen, sold Paris, April 26, 1907.
A copy attrib. JBI and HvBalen on panel (66 x 108 cm), sold Vienna, J.C. von Klinkosch, April 2, 1889, #30.
A poorly executed copy attributed to the workshop of JBII on panel (71.5 x 114.5 cm), sold London, Sotheby's, July 12, 2001, #108.
Some variants by Jan Breughel the Younger possibly inspired by this painting: One signed painting ("J Breugel" on lower left) with a nude figure of Venus on copper (58.1 x 89.7 cm), in Philadelphia, John G. Johnson Collection Philadelphia Museum of Art, inv. # 656. Another with a nude Venus sold London, Sotheby's, July 7, 2002, # 48 (panel, 57.8 x 89.5 cm). A version with a clothed figure of Venus, sold at auction in Hartford Connecticut, 1949 #8.
Moderately competent copy in chateau Hluboká (Frauenberg) in South Bohemia--panel, 73 x 114: published in Jaromír Šíp and O.J. Blažíček, Flämische Meister des 17. Jahrh., Prague 1963. Copy close to this one in collection Salomon Goldschmidt, 1898 where it formed part of series: RKD also has Taste from there, at least.
When these paintings were owned by Philip IV, they were kept in a reading room in the northern section of the Alcázar -- a relatively private chamber for thought and contemplation.