The young man on the left is a preacher and the man on the right with a microphone was an audience member asking a question. This sort of Q&A sessions or public forums are fairly common in NYC, especially at Union Square where freedom of expression is embrassed wholeheartedly.
But what is most interesting about this session was that it was very well-organized. Notice the large square area defined by the white tape and the smaller square where the man on the right was standing. If an audience member has a question, he or she was encouraged to stand in the small square and a microphone would be presented to him. I stayed and watched the debate for about half an hour and I am glad to report everyone was respectful, despite their differences in opinion.
It is common knowledge that certain topics are not appropriate for polite dinner conversation. Do you know what they are?