The people in the foreground are positioned in a very rhythmic way; suggesting movement in the piece. The economy in this piece is used to help create a sense of space; The lighthouse in the background is suggested with shapes. In addition all the individuals in the focal point is more detailed. The is a diagonal suggesting the direction everyone is coming from.
PS: The full name of the piece is "Fishing for Oysters at Cancale". I forgot to put it in the Title!