A lot of Rockets fans are tired of Dwight Howard's act. Which is nothing new for Howard, who has a tendency to wear out his welcome. This little seems to be one of those who have had enough.
As Howard was signing autographs a little girl can be seen waiting for him with her hand outstretched as if she was waiting for a high five. When Howard started towards her she hit him with a dab.
It appears as if Howard just brushed off the little girl's insult by hitting a dab of his own.
(h/t Guy Hut)