Despite the composition being muted and of bleak tones, there is a fun and lightness here. This is an emotional piece uncovering the fun in the dark the world was experiencing in the late 1800's.
New advancements made fun possible for a majority of people for the first time in human history, rather than just the super-wealthy.
This painting is part of a movement known as "l'art pour l'art," or "art for art's sake." In which members believed art should be produced without social values or function even political - an unheard-of consideration of our time. But, believe it or not, it was a reaction to the marxists' belief that all art should be political and enforce the message.
They believed art for its own sake is worthy, a reaction against not only Marxism but the Victorian era as well. The artist was very outspoken about these ideals, and even garnered controversy in a disagreement with an art critic accusing him of abusing the audience with the painting.