I came to this from the ever excellent BAGnewsNotes (which you should absolutely keep an eye on if you’re at all interested in visual media). It’s fascinating – not just the portraits, but the snippets of background that the photographer, Platon provides.
ETA: Oh, ACK. Seems that the flash doesn’t transfer from the New Yorker’s website. What you *should* see is a table of portraits of the world’s leaders, shot at the UN. Go look.