By the Riverside most probably depicts the Valley of the river Lys, where Claus painted many of his later landscapes. Here he reveals the influence of Jules Bastien-Lepage, Henri le Sidaner and Claude Monet, each of whom he had met on his, by now, frequent Paris sojourns. While the composition of By the Riverside reveals an Impressionistic treatment, especially to the open sunlit fields full of flowers, the figures preserve a realistic touch, never allowing the contours to totally evaporate into the surrounding diffused light. Unlike Bastien-Lepage, whose treatments of figures are usually unsentimental, Claus kept an anecdotal side to his painting, especially in his depictions of children.

Emile Claus studied at the Academy of Antwerp from 1870, and soon after exhibited at the Salons of Brussels, Ghent and Antwerp. The use of light played a great part in Claus's work and he increasingly embraced "plein air" painting. He exhibited with Belgian avant-garde groups and became a founding member of the group of artists known as Vie et Lumière.