Saudade (Longing), José Ferraz de Almeida Júnior
Link is to a zoomable version on the Google Art Project; there is a very high resolution downloadable file (138MB) on Wikimedia Commons; the original is in the Pinacoteca do Estado de São Paulo (no good images).
The subject of a young woman reading a letter, with either overt or implied emotional meaning, was popular in the 17th century and remained so through the 19th.
Here, 19th century Brazilian painter Almeida Júnior gives us the motif in its essentials, with a simple strong composition, and strong emotions in the woman’s face, despite the mouth being covered.