Picturing America--The Boating Party Revisited

The Boating Party by Marry Cassatt was profiled earlier this year.   This painting hangs near the computer area on the lower right.  The De Young Museum in San Francisco has an exhibit of French Impressionist paintings beginning this week and Cassatt was an artist of American Impressionsim. "As a woman, Cassatt was not permitted to enroll in the Ecole des Beaux-Arts, the leading art academy in France but found private instruction and educated herself...Years later, she recalled that her life had changed when she met the artist Edgar Degas, who invited her to joint the Impressionist circle.  Partly because women were not welcome in the Paris cafes where the Impressionists often discovered their subject matter, she specialized in domestic paintings, particularly of mothers and children."

In what ways do forms seem to move toward the edges of the painting?  What pulls the three figures together?  What might this feeling of expansion and contraction have to do with the subject of the painting?