In this photo, Enrique Peña Nieto displays a classic variation of a critical evaluation body language cluster. Note the President-elect is leaning away from the person of (dis)interest/disrespect. His torso is turned away as well and although his neck is partially rotated, his head is not fully turned towards the party of his (incomplete) attention. This necessitates that he gaze further to his left in order to make eye contact. We do not turn our torso/head/neck towards those who we don't like, don't respect or don't believe.
The future Mexican President's forefinger (aka index finger) is partially covering his mouth. This is a nonverbal signal that he doesn't believe and/or doesn't want to hear what is being said. In this critical evaluation cluster it is common for one digit (here his thumb) to extend up towards the ear (often it is the index finger with the middle finger covering the mouth instead) and the remaining digits are left to support the chin (or just appearing to support it).
Enrique also displays mild anger - with his eyebrows slightly contracted together as well as being depressed in a downwards (inferior) vector - particularly medially (the inner portions of the brows).
We do not see the position of Peña Nieto's left arm. In a critical evaluation cluster, it would be common for it to be folded across his lower torso with his left hand supporting the right elbow. Such body language beacons a further degree of emotional blocking. Although it is somewhat difficult to tell in this image, the President-Elect's torso also is leaning backwards in his chair. In this nonverbal context it indicates an anti-enthusiasm, aloofness and a disengagement from the speaker/his political ideology and/or the subject matter.
Analysis # 1720: Critical Evaluation, Disbelief, & a Partial Emblematic Slip - Valerie Trierweiler & Francois Hollande