Ms. Sofya Trotsenko, head of the Winzavod Center of Contemporary Art in Moscow, displays a tight-lipped false smile in this photograph. It is commonly seen when people are trying to give a polite impression, but their real emotions are not just neutral or disinterested, but considerably negative. People also display it when they are holding back a secret or have just spoken a partial truth. Note how Sofya's mid-face is tightened and her "smile", although it looks slightly upturned because of her downward head tilt, is horizontal. Her eyes are wide open which is never consistent with a true, felt smile.
Ms. Trotsenko's right hand is reaching across her front. It looks like she might be adjusting her hair or scratching - but this is a great example of a manipulator aka pacifier. In this setting, it is an indicator of defensive-anxiety.
Her downward head tilt is also consistent with a defensive posture. It can also be associated with anger, but because her forehead is relaxed and her eyebrows are not drawn together or downwardly displaced, we can be sure that here - Soyfa's head tilt is caused by a defensive emotional tone.