This image of Oscar Pistorius was taken several weeks ago during his trial of which he is accused of murdering his then girlfriend, Reeva Steenkamp (vs. accidentally killing her believing she was an intruder).
In this photo Mr. Pistorius is hugging a supporter. The identity of the woman is unknown (It may very well be that she is a member of the general public or an acquaintance) and we do not have this in a video format to put this moment in a greater context - yet there is a huge nonverbal lesson here.
Human-to-human contact is a relatively rare event - accounting for a very small percentage of any given day (even among family members). Whenever a hug is given, it should generally be given with two hands - unless a deliberate emotional distance is being sought or maintained. Thus a large majority of the time, when a higher level of affection is being projected or desired - a hug should be more fully expressed. Put down your phone, your car keys, your brief case, your purse, etc. - and be entirely present in the moment. This is particularly true when the other person is family, a lover or a good friend - but again, if a hug is being initiated - most of the time it should be done so sincerely and with some level of affection. If it is given sincerely and not returned similarly (or a vice versa) - this interpersonal information is very valuable and should be known.
The act of hugging well is a huge rapport builder. Don't pass up the opportunity to build rapport and affection in those who want or deserve it.
If the other person is not an individual with whom you have affection or feel socially obligated to hug - a one-armed hug is advisable and acceptable - however do so from a standpoint of full social-situational awareness - rather from one of naïveté, lack of mindfulness or poor body language knowledge/skill. There are of course numerous other nonverbal parameters of hugs which will either up-regulate or down-regulate the affection and intimacy level of the hug, kiss or other encounter (how many you can list?).
Nonverbal Communication Analysis No. 2927: Barack Obama regarding ISIS/ISIL - Atypical for the President
Nonverbal Communication Analysis No. 2785: Oscar Pistorius - Another Day of Testimony - Low Confidence Body Language Display
Nonverbal Communication Analysis No. 2809: Oscar Pistorius, Reeva Steenkamp and Kim Myers
Nonverbal Communication Analysis No. 2788: Oscar Pistorius Trial - Frustration & Anger
Nonverbal Communication Analysis No. 2750: Oscar Pistorius, Reeva Steenkamp and Lies
Nonverbal Communication Analysis No. 2919: Hillary Clinton and Barack Obama - Friends? - will they Hug it Out?