Why did the artist of the above painting place all the figures in rows in the picture plane?

I believe the artist did this, in order to demonstrate a story or event. all the people are lined up, instead of just one or two, because they are depicting a event. By looking at peoples expressions, mannerisms actions etc. it may give a hint to the events the art is centered around or based off of, something similar to propaganda demonstrating bias images in a similar manner

Explanation:

i believe it is a. a segment : )

well seeing i am an artist and i actually did a self portrait; i will describe how i painted it.   i used acrylic on a stretch canvas about 4 feet wide by 6 feet tall. i painted myself smiling in a soft pink long dress, white tile floor sitting on a white couch with a table behind and a vase of gorgeous flowers.   i also had a round white hat with a soft pink ribbon through it laying on the floor and on the table behind me was a lit candle. i kept it simple but soft and romantic.