They usually salute like this, however a lot of the time Hitler will salue like this(taken from Triumph of the Will). Why is that?
The Nazi salute was not only a greeting on itself, but also a gesture of obedience towards Hitler. Thus, when people would greet Hitler directly, he would respond with the gesture in the second photograph essentially symbolizing his 'acceptence' of the greetings towards him. On the Hitler hand, when Hitler would use the Nazi gesture first, for example at the end of a conference, others would follow with the salute accepting their obedience towards his words.
If I recall correctly I have also seen other higher ranking officers salute like that? Is it a salute only reversed for higher ranks?