Nevermind I just saw you were asking about the plaza area viewing. There is a photographer there during the party. Personally I prefer the garden viewing having done both.
I don't recall one at the party itself but there was one in the garden area. When I went in March it wasn't a sold out party and the photographer had a tripod and did pics during the fireworks. Last week when I went it was sold out, the photographer just did pictures before the show not during. So it's hard to say what you'll get for sure.