What is aggregation in SQL Profiler?
Say you aggregate on the LoginName column for instance. Then you get one blue section for each login name, and it will show you also how many events you have for that login name. To see the actual events, for that login, you look at the white rows under that blue row. In your example, you have aggregated over duration, and in the pic you included you have no two events with the same duration. Aggregating over something which has very few duplicates isn't very meaningful. You can think of aggregation such as a group by with a COUNT(*), that is what you see in the blue section for each value in the columns that you "grouped/aggregated" over.