The duet played by the couple may well refer to the harmony of true love, while the foot-warmer is usually interpreted as a symbol for the effort a man has to make in order to gain a woman's love.
The portrait in the right background is in the style of Michiel van Miereveld (1567 - 1641), and is probably of Prince Frederik Henrik of Orange (1584 - 1647), who became Stadholder of the Dutch Republic in 1625.
