It's worth note to examine the capabilities of the mind's eye in works such as Les Demoiselles d'Avignon and The Three Musicians. Picasso was a painter who was very aware of how things looked (different from the Expressionists' concern with the feelings attached to a given subject), and through this arena of visual aesthetics he experimented with form, shape, and design. His Cubist works demonstrate this; that he was interested in creating a specific image of an object which could convey a more geometrically accurate view. Collage-style art helped him to better narrow down shapes into pure, linear constructs, as seen in The Three Musicians. Eventually, he could narrow down the human face to pure shapes. This image of the Head of a Woman, from 1927, shows the extremes of Cubism.
Most people associate Pablo Picasso with this sort of style because it made his art the most instantly recognizable of nearly any other style. We can see this painting from afar and know that "it's a Picasso." And, while it bothers many people, the style is actually not one that is too complicated to grasp. Here we see the Head of a Woman, plain and simple. This is an image of an enclosed space with two eyes, two nostrils, a mouth with teeth, and crowning hair on top. It doesn't matter that the objects are totally distorted and misplaced; so long as all of the criteria are there, Cubism allows for the deformation of the subject in order to delve to the bottom of some element of greater verity, be it a visual, technical, or theoretical element. Though we see something that looks different, this is no less the Head of a Woman than this more realistically drawn chalk-on-paper rendering of the same title, produced five years earlier. On the flat tableau of the painter, both are equals in depiction of their subject.
The stunning realism of this work shows us Picasso's talent (as well as other works from various periods of the artist's life that show stunning accuracy and ability to paint well), and it reinforces the fact to us that the artist chose to paint the way he did, not for any lack of ability, but because he believed it theoretically significant to the development of art.