When we take pictures of an event we give emphasis on some major point. These points are different to different photographer. Like:
Some photographer focus on the
a) People (Both people who joins the event and who are interested about the event will like to see peoples of the event. Some will be happy see their faces and others will be happy to see who attended the ceremony)
b) Decoration (In many events new decoration, lighting had to included, people like to see and even organizers wants to show how they had decorated their party)
c) What happen (Everybody will like to see what the things happen in the party, so photographer may took every incidents picture, sometime funny pictures)
I think it will be good if anyone can take all pictures combining all 3 views given here.