Drawings like this by Picasso (in the 1920s, he created many such simple yet very creative and intuitive drawings of nudes in various postures) have been described by some art critics as 'phantasmagoric'. They may have been described like this because they provide what is just a very simple sketch of the human form which, thanks to the abundance of white space on the page, gives a sense of transparency rather than solidity. Similar contemporary drawings of nudes reclining on a left leg (and which are also often referred to by the same title: Nude Seated on Left Leg) were also created by the artists Modigliani and Matisse.
Picasso was not just an artist who worked in pen and ink. He worked in numerous different media, including collage, oil paints, sculpted clay and other ceramics (complete with glazes). Many of his paintings (a key example is Crying Woman) appear very complex and multilayered. Viewers might thus be tempted to view Nude Seated on Left Leg as a very simple art work, and one that represents nothing more than an idle sketch. Nevertheless, this is most definitely an important work of art in its own right. The bouncing, bounding lines, and the creation of a distinct personality for the woman depicted using just a few strokes of the ink pen, make Nude Seated on Left Leg unmistakably the work of Picasso.
Picasso was born in 1881 and he died in 1973. During his long life span, he created some of the most famous works of art in the Western world. One of his most well known works is Guernica, a copy of which is said to hang in the War Room of the Pentagon in the US. The original of Guernica can be visited in the Reina Sofia art gallery in Madrid, and it demonstrates that Picasso was intrigued not just by the human form (as is clear from Nude Seated on Left Leg) but also by the forms of animals in motion.