The term tronie means “face” in 17th century Dutch. It refers to a group of paintings that depicts an anonymous sitter, sometimes with an exaggerated expression or unusual and flamboyant costume.
Basically, they are character studies of an idealised version of a face or character that sparked the artists’ imagination. The difference between a portrait and a tronie is that in a portrait the sitter is known and the art piece has been commissioned whereas tronies were sold in the art market.
Artists turned to the tronie for many reasons. For example, it presents a unique opportunity to experiment with facial expressions and lighting.
Probably the most famous tronie is The Girl with a Pearl Earring by Johannes Vermeer (1632-1675). The painting depicts a Dutch girl dressed in oriental costume with a turban and an excessively big pearl earring.
The faces are almost a blank canvas that express an emotion or a story that is vague and elusive and keeps you guessing. You can keep coming back to them and read something different every time. The turban could be a symbol of high status, of servitude or even just a towel or cloth wrapping — another thing that adds to the ambiguity and layers of meaning.